Stock Average Price Calculator — Average Down After Buying More
CalculatorA stock average price calculator adds the current purchase cost and the new purchase cost, then divides by total shares to find the new average cost.
What is it
Average cost per share is total cost divided by total shares held. Buying more at a lower price lowers the average cost, while buying more at a higher price raises it. This tool can include fees in the total cost and show a break-even price, but it does not fetch market prices or provide investment advice.
How to use
- 1Enter current shares and current average cost.
- 2Enter additional shares, new purchase price, and any fees.
- 3Press calculate to see the new average, total shares, total cost, and current-price return.
Reference
| Current | New | New average |
|---|---|---|
| 10 × 50,000 | 10 × 40,000 | 45,000 |
| 30 × 70,000 | 20 × 55,000 | 64,000 |
| 5 × $100 | 5 × $80 | $90 |
Sources & standards
- Cost basis - U.S. SEC Investor.gov
- MDN Web Docs: Client-side web APIs - MDN Web Docs
FAQ
Are trading fees included?
If you enter total fees, they are added to total cost and reflected in the average and break-even price. Leave fees as 0 if you do not want to include them.
Does averaging down reduce risk?
Not necessarily. The average cost can fall, but total exposure also rises. This tool only performs arithmetic and is not investment advice.
Are share counts and prices sent to a server?
No. The calculation runs only in your browser and does not send input to a server.