The Stock Average Price Calculator helps investors calculate the average purchase price from multiple buy transactions.
Suitable for both averaging down and averaging up strategies. Includes profit/loss simulation with target selling price, standard stock exchange transaction fee calculations (buy 0.15%, sell 0.25%), and break-even price.
Disclaimer: Transaction fees vary between brokers. Results are simulations and not investment recommendations.
Calculator information
📋 How to use this calculator
- Enter your first transaction: purchase price per share and number of shares.
- Click the add transaction button to enter your second, third, and subsequent purchases.
- Check the include broker commission option (typical US online brokers: $0 for most stocks, but include any per-trade fees) for an accurate cost basis.
- View the resulting weighted average price (cost basis), which is calculated automatically.
- Enter a target sale price to simulate profit/loss and your break-even price.
- Use the results to evaluate your dollar-cost averaging strategy or to decide whether to average down or average up your position.
🧮 Weighted Average Price
Average = Sum(Price x Shares) / Sum(Shares)
- Price = purchase price per share for each transaction
- Shares = number of shares purchased in each transaction
- Total Cost Basis = Sum(Price x Shares) + Sum(Buy Commissions)
- Break-even Price = (Total Cost Basis x (1 + sell commission rate)) / Total Shares
- Profit = (Sale Price x Shares x (1 - sell commission rate)) - Total Cost Basis
Most major US brokers (Fidelity, Schwab, Robinhood, E*TRADE) charge $0 commission for online equity trades, though SEC and FINRA pass-through fees still apply on sells. Check your broker's fee schedule for full details.
💡 Worked example: Averaging down on a position after the price drops
Given:- Buy 1: 100 shares at $50.00 (cost $5,000)
- Buy 2: 200 shares at $45.00 (cost $9,000)
- Buy 3: 300 shares at $40.00 (cost $12,000)
- Assume $0 commission (typical US online broker)
Steps:- Total shares = 100 + 200 + 300 = 600 shares
- Total cost basis = $5,000 + $9,000 + $12,000 = $26,000
- Average price = $26,000 / 600 = $43.33 per share
- With $0 commissions, the break-even price equals the average cost
- Any sale above $43.33 (after SEC/FINRA fees, typically less than $0.01 per share) generates a profit
Result: Average cost basis is $43.33 per share; break-even is essentially the same. Once the price rises above $43.33, the position is profitable.
❓ Frequently asked questions
What is dollar-cost averaging and is it always profitable?
Dollar-cost averaging (DCA) is the strategy of buying additional shares as the price falls to lower your average cost basis. It works when the company's fundamentals remain strong and the price eventually recovers. It becomes risky if the stock keeps declining or if the underlying business is deteriorating. Always pair DCA with fundamental analysis - do not average down simply because a stock looks cheap. Avoid the strategy on speculative names or companies with persistent losses.
What are typical stock trading fees in the US?
Most major US brokers (Fidelity, Schwab, Robinhood, E*TRADE, Vanguard) charge $0 commission for online equity trades. However, the SEC charges a small transaction fee on sales (currently around $0.00278 per $1,000 of proceeds) and FINRA charges a Trading Activity Fee (about $0.000166 per share, capped at $8.30 per trade). Options trades usually still have per-contract fees (typically $0.50 to $0.65). Check your broker's fee schedule for full details.
What is the break-even price and how does it differ from the average price?
Average price is the weighted average cost of your shares without factoring in fees. Break-even price is the minimum sale price needed to recoup all costs after commissions and regulatory fees. In the US, with $0 commissions, the two are nearly identical - the gap is only the small SEC/FINRA pass-through fees on the sale. Selling above the break-even price produces a profit; below it produces a loss. Note that taxes on capital gains are a separate consideration.
When does averaging up make sense?
Averaging up is appropriate when a stock is trending higher and fundamentals continue to strengthen (revenue growth, expanding margins, strong management). It works best with blue chips or quality growth stocks in confirmed uptrends. The risk is that your average cost rises, shrinking your profit margin and amplifying losses if the trend reverses. Disciplined investors typically scale in gradually with smaller position sizes on each subsequent buy.
Do dividends affect the average price calculation?
Dividends do not change your average cost mathematically, but they do affect your total return. Some investors track an adjusted cost basis: Adjusted Cost = (Total Cost - Total Dividends Received) / Total Shares. This is useful for long-term performance evaluation. In the US, qualified dividends are taxed at 0%, 15%, or 20% depending on income bracket, while ordinary dividends are taxed as regular income. Reinvested dividends (DRIP) increase your share count and your cost basis.
📚 Sources & references
Last updated: May 11, 2026