🐱 Cat Pregnancy Calculator
Calculate accurate due date based on breeding date and breed
📝 Pregnancy Information
📅 Due Date
Enter breeding date and breed,
then click Calculate
📋 Key Information
Breed-specific information
will appear here
📚 Pregnancy Stage Guide
🔬 Development:
- Fertilized eggs implant into uterine wall
- External changes are difficult to detect
- Minimal changes in appetite and behavior
⚕️ Care:
- Maintain normal care routine
- Minimize stress
- Be cautious with medications
🔬 Development:
- Pregnancy detectable via ultrasound (days 20-24)
- Nipples begin to turn pink
- Slight increase in appetite or morning sickness symptoms
⚕️ Care:
- Veterinary examination recommended
- Begin transitioning to high-nutrition food
- Limit strenuous activity
🔬 Development:
- Abdomen begins to swell visibly
- Noticeable weight gain
- Fetal movement may be felt
- Mammary glands develop and nipples enlarge
⚕️ Care:
- Feed pregnancy-specific cat food
- Divide meals into 3-4 feedings per day
- Begin preparing birthing area
- Restrict jumping and climbing to high places
🔬 Development:
- Abdomen very enlarged with active fetal movement
- Milk may leak from mammary glands
- 24-48 hours before delivery: temperature drop (below 99.5°F/37.7°C)
- Nesting behavior begins
⚕️ Care:
- Prepare birthing box in quiet, warm location
- Monitor temperature twice daily
- Keep veterinarian’s emergency contact ready
- Watch for labor signs: restlessness, decreased appetite, panting
🚨 Emergency Signs:
- No signs of labor after day 72
- No kitten delivered 2+ hours after labor begins
- Green discharge appears before kitten delivery
- Heavy bleeding or foul-smelling discharge
🔬 Calculation Methods
Breeding Date-Based
The most basic calculation method applying breed-specific average gestation periods. Calculates due date by adding breed-specific average days to breeding date.
Ultrasound-Based
Uses ultrasound measurements (CRL, GSD, BP, BD) to accurately determine current gestational age and calculate remaining time. Useful when breeding date is uncertain.
Accuracy & Limitations
This calculator is based on scientific research but may have a margin of error of ±2-4 days. Always consult with a veterinarian for accurate diagnosis and care.
⚠️ Important Notice: This calculator provides estimates based on scientific research. Actual delivery dates may vary due to individual differences. Always consult with a veterinarian. Contact your vet immediately if delivery occurs before day 60 or if pregnancy extends beyond day 72.
The cat pregnancy calculator is a professional web tool that calculates the expected due date based on mating date and breed information. Based on international veterinary research data, it accurately applies the average gestation period for each breed to scientifically analyze your cat’s expected delivery date and current pregnancy stage.
Beyond simple date calculations, it provides precise calculations using ultrasound measurements, breed-specific analysis, and stage-by-stage pregnancy management guides to help expectant pet parents prepare for a safe and healthy delivery.
Key Features
1. Breed-Specific Customized Calculation
Applies average gestation period data for 11 major breeds including Siamese, Persian, and Maine Coon. Each breed has different gestation periods ranging from 63 to 66 days, and these differences are accurately reflected in calculating the expected delivery date.
2. Ultrasound Measurement-Based Calculation
If the exact mating date is unknown, you can input ultrasound data measured by a veterinarian (CRL, GSD, BP, BD) to calculate the current gestational week and expected delivery date. Internationally validated veterinary formulas are applied.
3. Real-Time Pregnancy Progress Tracking
Visually displays current pregnancy days and time remaining until delivery for at-a-glance progress monitoring. Check pregnancy stages intuitively with progress bars and weekly timelines.
4. Breed-Specific Information Provision
Provides detailed information based on actual veterinary research data, including cesarean section rates, dystocia risk levels, and special care requirements for each breed. Check breed-specific precautions in advance, such as Persian brachycephalic characteristics or Oriental’s high dystocia rate.
5. Stage-by-Stage Pregnancy Management Guide
Provides detailed guidance on developmental processes and management methods for each stage: early (1-3 weeks), ultrasound confirmation (3-4 weeks), mid (4-6 weeks), and late (6-9 weeks). Clearly presents precautions and veterinary checkup timings for each stage.
6. Emergency Alert System
Provides automatic warning features for premature birth risks under 60 days or overdue situations exceeding 72 days. Detects critical zones where survival rates sharply decrease and recommends immediate veterinary consultation.
How to Use
Step 1: Enter Basic Information
Select your cat’s name and breed. When you select a breed, the average gestation period for that breed is automatically applied. For mixed breeds, the average value of 65.1 days is applied.
Step 2: Enter Mating Date
Enter the first day of mating. If mating occurred over multiple days, enter the first day as reference. Once entered, the elapsed days are automatically displayed.
Step 3: Enter Ultrasound Data (Optional)
If the mating date is uncertain or you want more accurate calculations, you can activate the ultrasound toggle and enter measurements. Accurately enter the CRL, GSD, BP, BD values and measurement date provided by your veterinarian.
Step 4: Calculate and Check Results
Click the calculate button to display the expected delivery date, expected range (±4 days), current pregnancy progress, breed-specific characteristics, and current stage management methods all at once.
Calculation Method Explanation
Mating Date-Based Calculation
The most basic calculation method, adding the breed-specific average gestation period to the mating date to determine the expected delivery date. The average gestation period for all cats is 65.1 days, and 95-97% of cats give birth between 61-70 days.
Formula: Expected Delivery Date = Mating Date + Breed-Specific Average Gestation Days
Expected Range: Considering individual variations, a range of ±4 days from the expected date is provided.
Ultrasound-Based Calculation
Uses veterinary-validated formulas to determine current gestational weeks from ultrasound measurements and calculates remaining time based on a 61-day standard.
- CRL (Crown-Rump Length): Gestation Days = (CRL + 4.2165) ÷ 0.2423
- GSD (Gestational Sac Diameter, before 40 days): Gestation Days = (6 × GSD) + 20
- BP (Biparietal Diameter, after 40 days): Gestation Days = (25 × BP) + 3
- BD (Body Diameter, after 40 days): Gestation Days = (11 × BD) + 21
Ultrasound-based calculations have an accuracy of ±2 days and are particularly useful when the mating date is uncertain.
Breed-Specific Gestation Period Data
This calculator applies the following breed-specific data based on international veterinary research (PMC, UK study of 1,056 cats, etc.).
| Breed | Average Gestation Period | Cesarean Section Rate | Characteristics |
|---|---|---|---|
| Siamese | 63 days | 11.6% | Short gestation but high dystocia risk |
| Persian | 65 days | 6.6% | Brachycephalic breed requiring birth attention |
| Oriental Shorthair | 66.2 days | 15.2% | Longest gestation period and highest cesarean rate |
| British Shorthair | 65.3 days | 4.8% | Relatively stable pregnancy progression |
| Maine Coon | 65.5 days | 3.9% | Large breed, very low cesarean rate |
| Burmese | 64.3 days | 5.0% | Average pregnancy characteristics |
| Birman | 64.9 days | 4.5% | Gentle temperament, easy to manage |
| Devon Rex | 64.7 days | 5.2% | Small breed, temperature management important |
| Korat | 63 days | 4.0% | Similar pregnancy characteristics to Siamese |
| Abyssinian | 65.8 days | 5.8% | Active nature requires safety management |
| Tonkinese | 65 days | 5.0% | Burmese and Siamese cross |
| Mixed Breed | 65.1 days | 5.0% | Individual variation can be significant |
Stage-by-Stage Pregnancy Guide
Weeks 1-3 (Early Stage)
Developmental Process
- Fertilized egg begins implantation in uterine wall
- External changes difficult to confirm
- Minimal appetite and behavior changes
Management Methods
- Manage as usual
- Minimize stress
- Be cautious with medication
- Limit rough play or jumping
Weeks 3-4 (Ultrasound Confirmation Period)
Developmental Process
- Pregnancy confirmation possible via ultrasound (20-24 days)
- Nipples begin turning pink
- Slight appetite increase or morning sickness symptoms
- May become quieter or more affectionate than usual
Management Methods
- First veterinary checkup recommended (pregnancy confirmation)
- Begin transition to high-nutrition food
- Limit vigorous activity
- Provide quiet and stable environment
Weeks 4-6 (Mid Stage)
Developmental Process
- Abdomen begins visibly swelling
- Noticeable weight gain
- Fetal movement can be felt (from week 5)
- Mammary glands develop and nipples enlarge
- Appetite increases significantly
Management Methods
- Feed pregnancy-specific or kitten food
- Divide meals into 3-4 times daily
- Begin preparing birthing area
- Completely restrict jumping or climbing
- Mid-term veterinary checkup (week 5 recommended)
Weeks 6-9 (Late Stage/Birth Preparation)
Developmental Process
- Abdomen very large with active fetal movement
- Milk may appear from mammary glands (colostrum)
- 24-48 hours before birth: temperature drop (below 37.7°C)
- Nesting behavior begins
- Anxious or follows owner around
- Appetite may decrease (birth imminent)
Management Methods
- Prepare birthing box in quiet, warm location
- Measure temperature twice daily (rectal thermometer)
- Prepare veterinary emergency contact
- Observe birth signs: anxiety, appetite loss, panting, nesting
- Prepare birthing supplies: clean towels, sterilized scissors, thread, thermometer
Emergency Signs
- No birth signs after 72 days
- No kitten delivery 2+ hours after labor begins
- Green discharge before kitten delivery
- Heavy bleeding or foul-smelling discharge
- Extreme pain or lethargy
Important Information and Precautions
Minimum Viable Period
- Manage as usual
- Minimize stress
- Be cautious with medication
- Limit rough play or jumping
Weeks 3-4 (Ultrasound Confirmation Period)
Developmental Process
- Pregnancy confirmation possible via ultrasound (20-24 days)
- Nipples begin turning pink
- Slight appetite increase or morning sickness symptoms
- May become quieter or more affectionate than usual
Management Methods
- First veterinary checkup recommended (pregnancy confirmation)
- Begin transition to high-nutrition food
- Limit vigorous activity
- Provide quiet and stable environment
Weeks 4-6 (Mid Stage)
Developmental Process
- Abdomen begins visibly swelling
- Noticeable weight gain
- Fetal movement can be felt (from week 5)
- Mammary glands develop and nipples enlarge
- Appetite increases significantly
Management Methods
- Feed pregnancy-specific or kitten food
- Divide meals into 3-4 times daily
- Begin preparing birthing area
- Completely restrict jumping or climbing
- Mid-term veterinary checkup (week 5 recommended)
Weeks 6-9 (Late Stage/Birth Preparation)
Developmental Process
- Abdomen very large with active fetal movement
- Milk may appear from mammary glands (colostrum)
- 24-48 hours before birth: temperature drop (below 37.7°C)
- Nesting behavior begins
- Anxious or follows owner around
- Appetite may decrease (birth imminent)
Management Methods
- Prepare birthing box in quiet, warm location
- Measure temperature twice daily (rectal thermometer)
- Prepare veterinary emergency contact
- Observe birth signs: anxiety, appetite loss, panting, nesting
- Prepare birthing supplies: clean towels, sterilized scissors, thread, thermometer
Emergency Signs
- No birth signs after 72 days
- No kitten delivery 2+ hours after labor begins
- Green discharge before kitten delivery
- Heavy bleeding or foul-smelling discharge
- Extreme pain or lethargy
Important Information and Precautions
Minimum Viable Period
- First veterinary checkup recommended (pregnancy confirmation)
- Begin transition to high-nutrition food
- Limit vigorous activity
- Provide quiet and stable environment
Weeks 4-6 (Mid Stage)
Developmental Process
- Abdomen begins visibly swelling
- Noticeable weight gain
- Fetal movement can be felt (from week 5)
- Mammary glands develop and nipples enlarge
- Appetite increases significantly
Management Methods
- Feed pregnancy-specific or kitten food
- Divide meals into 3-4 times daily
- Begin preparing birthing area
- Completely restrict jumping or climbing
- Mid-term veterinary checkup (week 5 recommended)
Weeks 6-9 (Late Stage/Birth Preparation)
Developmental Process
- Abdomen very large with active fetal movement
- Milk may appear from mammary glands (colostrum)
- 24-48 hours before birth: temperature drop (below 37.7°C)
- Nesting behavior begins
- Anxious or follows owner around
- Appetite may decrease (birth imminent)
Management Methods
- Prepare birthing box in quiet, warm location
- Measure temperature twice daily (rectal thermometer)
- Prepare veterinary emergency contact
- Observe birth signs: anxiety, appetite loss, panting, nesting
- Prepare birthing supplies: clean towels, sterilized scissors, thread, thermometer
Emergency Signs
- No birth signs after 72 days
- No kitten delivery 2+ hours after labor begins
- Green discharge before kitten delivery
- Heavy bleeding or foul-smelling discharge
- Extreme pain or lethargy
Important Information and Precautions
Minimum Viable Period
- Feed pregnancy-specific or kitten food
- Divide meals into 3-4 times daily
- Begin preparing birthing area
- Completely restrict jumping or climbing
- Mid-term veterinary checkup (week 5 recommended)
Weeks 6-9 (Late Stage/Birth Preparation)
Developmental Process
- Abdomen very large with active fetal movement
- Milk may appear from mammary glands (colostrum)
- 24-48 hours before birth: temperature drop (below 37.7°C)
- Nesting behavior begins
- Anxious or follows owner around
- Appetite may decrease (birth imminent)
Management Methods
- Prepare birthing box in quiet, warm location
- Measure temperature twice daily (rectal thermometer)
- Prepare veterinary emergency contact
- Observe birth signs: anxiety, appetite loss, panting, nesting
- Prepare birthing supplies: clean towels, sterilized scissors, thread, thermometer
Emergency Signs
- No birth signs after 72 days
- No kitten delivery 2+ hours after labor begins
- Green discharge before kitten delivery
- Heavy bleeding or foul-smelling discharge
- Extreme pain or lethargy
Important Information and Precautions
Minimum Viable Period
- Prepare birthing box in quiet, warm location
- Measure temperature twice daily (rectal thermometer)
- Prepare veterinary emergency contact
- Observe birth signs: anxiety, appetite loss, panting, nesting
- Prepare birthing supplies: clean towels, sterilized scissors, thread, thermometer
Emergency Signs
- No birth signs after 72 days
- No kitten delivery 2+ hours after labor begins
- Green discharge before kitten delivery
- Heavy bleeding or foul-smelling discharge
- Extreme pain or lethargy
Important Information and Precautions
Minimum Viable Period
The minimum gestation period for feline fetal viability is 60 days. Birth before 60 days results in sharply decreased survival rates, so contact your veterinarian immediately if premature labor signs appear.
Normal Delivery Range
90.2% of all cats give birth between 63-67 days, and 95-97% give birth between 61-70 days. Cases outside this range may require veterinary intervention.
Overdue Risk
Exceeding 72 days of gestation poses risks of fetal post-maturity. If there are no labor signs after 71 days, consult your veterinarian to consider induced labor or cesarean section.
Calculation Accuracy
While this calculator is based on scientific research, there may be a ±2-4 day margin of error. Various factors including individual variation, nutritional status, stress levels, and litter size can affect the actual delivery date.
Veterinary Checkup Schedule
- Week 3: First checkup and pregnancy confirmation (ultrasound)
- Week 5: Mid-term checkup and fetal health confirmation
- Week 8: Final checkup and birth preparation consultation
- Emergency: Immediate contact upon detecting any abnormal signs
Frequently Asked Questions
Q. What if I don’t know the exact mating date?
A. Use the ultrasound measurement feature. Enter the CRL, GSD, BP, BD values measured by your veterinarian to calculate the current gestational week and determine the expected delivery date. Selecting the appropriate measurement value based on the timing is important.
Q. What value should be used for mixed breeds?
A. Mixed breeds use the average value for all cats of 65.1 days. However, individual variation can be significant, so keep in mind delivery may occur within the 61-70 day range.
Q. The calculation result differs from what my vet said?
A. Veterinarians make more accurate judgments through direct examinations including ultrasound and palpation. The calculator is a reference tool, and the veterinarian’s diagnosis always takes priority.
Q. The due date has passed but there are no birth signs.
A. Since the due date has a ±4 day range, 2-3 days after the due date is still within normal range. However, consultation with a veterinarian is needed if there are no signs after 71 days, and hospital visit is necessary immediately after 72 days.
Q. Does a larger litter mean earlier delivery?
A. Some studies report a tendency for slightly earlier delivery with larger litters, but the difference is minimal at about 1-2 days. Breed and individual characteristics have a greater impact.
Q. When is the best time for an ultrasound?
A. The first ultrasound is recommended 20-24 days (week 3) after mating. Pregnancy can be confirmed at this time, and a re-examination around 35-40 days confirms litter size and health.
Scientific Basis
This calculator was developed based on the following validated veterinary research.
Main References
- Clinical management of pregnancy in cats – PMC scientific paper (PMC7103129)
- Feline breeding and pregnancy management – PMC scientific paper (PMC9099157)
- A questionnaire-based study of gestation in UK pedigree cats – UK large-scale study of 1,056 cats (PMC10832861)
- Reproductive Results of Selected Cat Breeds – Maine Coon, British Shorthair, Devon Rex specialized study (PMC12299069)
- MSD Veterinary Manual – International veterinary professional resources
Data Reliability
All breed-specific data and calculation formulas use those validated by internationally recognized veterinary journals and large-scale clinical studies. Ultrasound measurement formulas apply standard formulas taught in veterinary schools.
Disclaimer
This cat pregnancy calculator is an estimation tool based on scientific research. Calculation results should be used for reference purposes only and cannot replace actual medical diagnosis or treatment.
Cat pregnancy and delivery are affected by various factors with significant individual variation. Accurate pregnancy diagnosis, delivery date confirmation, and health status evaluation must be conducted through direct veterinary examination.
If emergency situations occur such as premature birth signs before 60 days, overdue situations exceeding 72 days, abnormal discharge, or extreme pain, please contact an animal hospital immediately.
The developers and operators assume no legal responsibility for any results arising from the use of this calculator.
Closing
The cat pregnancy calculator was developed to help expectant pet parents safely prepare for the delivery of their beloved cats. While it provides accurate information based on scientific data, the most important things are regular veterinary checkups and careful observation.
Pregnancy and delivery are special and important times for both cats and their owners. We hope this tool provides small assistance in that precious journey. We wish you a healthy delivery.