Stock/Crypto DCA Calculator
Average cost guide
Check the new average cost before adding to a position
When you add shares or crypto to an existing position, the lower entry price is only one part of the story. This DCA calculator combines your current quantity, current average cost, additional quantity, and additional buy price so you can see the new average cost, breakeven price, total quantity, and target-price scenarios in one place.
Start with your current position, then test the next buy
- Enter your current quantity and average cost first. Those two values become the base cost of the position you already hold.
- Add the planned quantity and buy price. Changing either value updates the new average cost and total quantity immediately.
- Use the quick price buttons as rough scenarios. The -5% to -30% buttons fill a buy price below your current average cost; they do not fetch a live market quote.
- Turn fees and tax on only when you want a breakeven estimate. Buy fees affect the average cost, while sell fees and tax affect the breakeven price.
The important inputs are quantity, price, and optional trading costs
Current quantity
The number of shares, coins, or units you already hold.
Current average cost
The average entry price shown in your brokerage or exchange account.
Additional quantity and price
The order you are considering now. These two fields drive the average-cost change.
Fee and tax fields
Optional percentages for a closer breakeven view when trading costs matter.
The calculator weights the old and new cost by quantity
Average cost is not a simple midpoint between two prices. A larger additional buy has more weight, so the new average moves closer to the additional buy price.
A quick example with 100 shares and 50 more shares
Suppose you hold 100 shares at $50.00 and consider buying 50 more shares at $45.00, with fees turned off.
What this means
The average cost falls from $50.00 to about $48.33, but the total invested amount increases. The lower average cost should be read together with position size and downside risk.
Read the result as a position-size check, not a buy signal
New average cost
The updated cost basis after the additional buy.
Change amount and percent
How much the average cost moved compared with the current average.
Breakeven price
The price that would roughly cover the average cost plus enabled sell costs.
Target scenarios
Estimated profit or loss at selected future prices, useful for comparing exits.
Lowering the average cost can still increase total risk
- Position size grows. A lower average cost often comes with more money exposed to the same asset.
- Fees vary by broker or exchange. Use your own fee schedule if the default percentage does not match your account.
- Taxes are simplified. The calculator treats tax as a percentage input and does not replace tax advice.
Use the result as a planning check before placing an order. It cannot tell you whether the asset is cheap or whether the trend will recover.
DCA calculator FAQ
Is DCA the same as averaging down?
Not exactly. DCA usually means spreading purchases across time or price levels, while averaging down describes buying more below your current cost. This calculator focuses on the average-down situation: an existing position plus a planned additional buy.
What changes when fees and tax are enabled?
A buy fee can slightly raise the new average cost because it is added to the additional purchase cost. Sell fees and tax raise the breakeven price, since the position needs a higher exit price to cover those costs.
Can I use this for crypto as well as stocks?
Yes, if the asset can be described by quantity and buy price. Crypto exchanges may have different fee tiers, minimum order sizes, and quote currencies, so compare the calculator result with your account records.
What do the -5% quick buttons use as the base?
They use the current average cost field as the base and fill an additional buy price below that number. They are scenario shortcuts, not live market prices.
Does a lower average cost mean lower risk?
No. The average cost can go down while the total amount invested goes up. If the price keeps falling, the larger position can produce a larger loss.