Average Down Calculator (Stocks & Crypto)
Enter your position and the additional buy on the left; the new average cost updates instantly on the right, with a price comparison and sell scenarios below.
Input
Advanced assumptions (fees & tax)
Results update automatically as you type.
Result
- Average cost change
- —
- Total quantity
- —
- Total invested
- —
- Breakeven (fee-adjusted)
- —
Price comparison
Sell-price scenarios
| Scenario | Sell price | Realized P/L |
|---|---|---|
| Results update automatically as you type. | ||
This is arithmetic on your own assumptions, not investment advice. Averaging down increases your total invested amount and concentration risk.
ready to use.
- Visible firstKeep the input and result positions clear.
- Results firstPut the main number up front and keep the process secondary.
- Less to askNo sign-up or extra information before using the tool.
Deciding an average-down with numbers, not gut feeling
Averaging down means buying more of a position after its price falls below your average cost, lowering that average. This calculator shows the outcome before you commit: the new average cost, how much it moves, the fee-adjusted breakeven price, and realized profit or loss at different sell prices.
A lower average cost means a smaller rebound is needed to break even — it does not erase the loss. Because your total invested amount grows, the same percentage drop costs more money after the buy.
The formula: total invested ÷ total quantity
The tool adds your existing investment to the new purchase and divides by the combined quantity. A buy fee, if set, is applied to the new purchase and slightly raises the acquisition cost.
- Existing investment = quantity held × average cost
- New purchase = quantity × buy price × (1 + buy fee)
- New average cost = (existing + new purchase) ÷ total quantity
Screen flow: input, new average, comparison
Change any value on the left and the right panel recalculates without a button. The price bars below show where the current average, buy price, new average, and breakeven sit; the scenario table turns sell prices into realized P/L.
Breakeven sits slightly above the new average
Selling costs fees (and, in some markets, transaction tax), so breaking even requires a slightly higher price than the new average. With fees at zero, breakeven equals the new average exactly.
- Breakeven = total invested ÷ (total quantity × (1 − sell fee − tax))
- Fee schedules vary by broker and product
- Replace the defaults with your account’s real rates
Drop chips fill the buy price fast
The −5% to −30% chips fill the buy price at that discount from your current average cost — a quick way to turn “I’ll buy if it drops another 10%” into concrete numbers.
Default example: 20 shares at $150 + 10 at $120
The page default with zero fees. Follow the four numbers through the formula.
- Existing investment
- 20 × 150 = 3,000
- New purchase
- 10 × 120 = 1,200
- New average cost
- 4,200 ÷ 30 = 140.00
- Change
- ▼6.67% (10.00)
Sample button: a deeper add
The sample doubles the position at $100: 20 held plus 20 more.
- New purchase
- 20 × 100 = 2,000
- New average cost
- 5,000 ÷ 40 = 125.00
- Breakeven
- 125.00 with zero fees
- Reading
- A bigger add pulls the average harder toward the new price
Read sell price and realized P/L together
Each scenario row prices a sale from −10% to +50% around breakeven. Realized P/L is after sell fees, so find the row closest to your target and judge by what actually lands in the account. The breakeven row is the zero line.
The risk: a lower average is not lower risk
Adding to a falling position concentrates more money in one name. If the downtrend continues, the loss in dollars grows even though the average is lower. FINRA and other regulators warn about chasing falling positions and single-position concentration alongside any staged-buying strategy.
- Check why the price fell before adding
- Confirm the total position stays within what you can afford
- This page is an educational calculator, not investment advice
Average-down FAQ
What does this calculator compute?
The new average cost after adding to a position, the percentage and absolute change, the fee-adjusted breakeven price, and realized profit or loss at sell prices from −10% to +50% around breakeven.
What formula is used for the new average cost?
(quantity held × average cost + added quantity × buy price × (1 + buy fee)) ÷ total quantity — a weighted average that leans toward whichever side has more quantity.
Why is breakeven above the new average cost?
Because selling costs fees and, in some markets, transaction tax. Breakeven = total invested ÷ (total quantity × (1 − sell fee − tax)); with zero fees it equals the new average.
Can I enter fractional quantities for crypto?
Yes. Quantity fields accept up to eight decimal places, and price fields format thousands separators as you type.
Is averaging down always a good idea?
No. It reduces the rebound needed to break even but increases your total invested amount and concentration in one position. Understand why the price fell first; this tool only quantifies the outcome.
Reviewed: 2026-07-11. Fee defaults are examples; replace them with your broker’s real rates.