Average cost calculator
Add each purchase with its price and number of shares and get your average cost per share. Useful for every investor who buys the same thing more than once.
Average cost per share
At $55.00 a share you are ahead by $5.00 per share.
How this calculator works
Add every purchase with its number of shares and price. The calculator divides the total you spent by the total shares you own.
If you buy the same amount of money each time (dollar-cost averaging), you automatically buy more shares when prices are low, which pulls your average cost down.
Average cost = Σ(shares × price) ÷ Σ sharesCommon questions
Should I include fees?
For a precise cost basis, add fees to the price of each purchase. Your broker's cost basis report includes them.
What does "averaging down" mean?
Buying more after the price has fallen, which lowers your average cost. It helps only if the investment eventually recovers.
Is average cost the same as cost basis for taxes?
Not always. US brokers often use first-in, first-out for individual stocks; mutual funds can use average cost. Check your broker's method.
FatDCA calculators are educational estimates, not investment, tax or legal advice. Results depend on the assumptions you enter, and past returns do not predict future returns.
One small deposit a week, for your brain
- 1chart from real data
- 1idea in plain English
- 1thing to do this week