Average Cost
Add your buys. See your average and breakeven.
Costs
A flat amount, charged on every buy.
A flat amount, charged once when you sell.
1 for shares or coins, 100 for standard option contracts.
Adds unrealized profit or loss below.
Result
Add a price and a quantity to see your average.
Bring the average to a target
Down or up: enter the average you want and the price you would buy at, and see how many more units it takes.
Add your buys above first.
Long positions only. Fees are flat amounts, not percentages. Prices carry no currency. Math only, not financial advice. Nothing you type here is stored or sent anywhere.
About
Enter each buy as a price and a quantity and get your average price per unit, your total cost and your breakeven once fees are counted. Add the price you are looking at and it shows your unrealized profit or loss. A solver at the bottom tells you how many more units to buy, at a price you choose, to bring your average to a target.
- How do I calculate the average cost of shares bought at different prices?
- Multiply each price by its quantity, add those up, and divide by the total quantity. Buying 100 at 10 and 50 at 8 gives (1,000 + 400) / 150 = 9.33 per share. Buying more units at a lower price pulls the average down, weighted by how many you bought.
- What is the difference between average price and breakeven?
- The average price ignores fees. Breakeven adds every buy fee and the fee to sell, then spreads that over your units, so it is the price you need to sell at to come out even.
- What does averaging down mean?
- Buying more of something after its price has fallen, which lowers your average cost per unit. It does not change what your holding is worth, and putting more money into a falling position adds risk as well as lowering your average.
- How many shares do I need to buy to reach a target average?
- With Q units at an average of A, buying n more at price P gives (Q x A + n x P) / (Q + n). Solving for a target T gives n = Q x (A - T) / (T - P). For example, 100 units at an average of 10, buying at 5 to reach 8, needs 66.7, which the tool rounds up to 67. It only works when the buy price is below the target (to average down) or above it (to average up).
- Can I use it for options?
- Yes. Enter the number of contracts as the quantity, the premium as the price, and set the multiplier to 100 for standard contracts so the money amounts are right. Averages and breakeven stay per unit.
- Does it handle short positions, taxes or currencies?
- No. It is for long positions, it treats fees as flat amounts, and prices carry no currency. It does not know about taxes, tax lots or wash-sale rules.
- Is this financial advice?
- No. It is arithmetic on the numbers you enter. Nothing you type is stored or sent anywhere; the calculation runs in your browser.