Average Down Calculator
You bought 100 shares of a company at $50 each. The stock drops to $40, and you decide to buy 50 more shares. What is your new average price per share? An average down calculator answers that question instantly by computing the weighted‑average cost of all your purchases.
How Do You Calculate the New Average Cost Per Share?
Averaging down recalculates your cost basis using every buy order, not just the most recent one. The formula:
New Average Price = (Original Quantity × Original Price + New Quantity × New Price) ÷ (Original Quantity + New Quantity)
Say you start with 100 shares at $50 ($5,000 total cost). You add 50 shares at $40 ($2,000). The math is simple:
(100 × 50 + 50 × 40) ÷ (100 + 50) = (5,000 + 2,000) ÷ 150 = 7,000 ÷ 150 = $46.67 per share.
Your average cost dropped from $50 to $46.67. If the stock later trades above $46.67, you are in profit on the entire position even though you never bought that exact price.
The calculator below performs this weighting automatically. Enter the number of shares and price for your first purchase, then the shares and lower price for the additional buy. The tool instantly displays your new average cost, total invested, and breakeven price.
Disclaimer: This tool is for educational purposes only and does not constitute financial, tax, or investment advice. Past performance does not guarantee future results. Always assess your own risk tolerance and consult a qualified financial advisor before making investment decisions.
What Is Averaging Down and Why Do Investors Use It?
Averaging down is the practice of purchasing more shares of a stock after its price has fallen, with the goal of lowering the average cost per share. For long‑term investors, this can turn paper losses into a more favorable cost basis – but only if the business’s fundamentals haven’t deteriorated.
Three scenarios where investors commonly average down:
- The market overreacts. A strong company drops 15% on short‑term news that doesn’t affect its long‑term earnings.
- Systematic investing. An investor builds a position gradually, adding more when prices dip.
- Managing a portfolio. The strategy can help turn an underperforming holding into a larger position at a better average price.
When Is Averaging Down a Smart Move?
The lower average price looks appealing on a spreadsheet, but averaging down carries real risk. Before you buy more, check these conditions:
- The company is still healthy. Revenue, margins, and debt levels are stable. A price drop driven by panic is different from one driven by a failing business.
- You have spare capital. Never commit money you need for other obligations just to lower an average price.
- The drop is not a permanent impairment. Technology shifts, regulatory bans, or fraud can destroy value permanently. In those cases, averaging down leads to larger losses.
Averaging down works best when the stock’s intrinsic value remains above the reduced price. If the original thesis is broken, cutting the position is often wiser.
Averaging Down vs. Dollar‑Cost Averaging
Despite similar math, these two are not the same:
| Aspect | Averaging Down | Dollar‑Cost Averaging |
|---|---|---|
| Trigger | Price drop on a stock you already own | Calendar schedule (e.g., monthly) |
| Objective | Lower a specific position’s cost basis | Build a position over time without timing the market |
| Risk | Concentrates more capital in a falling asset | Diversifies timing; you buy fewer shares when expensive and more when cheap |
Many long‑term investors use dollar‑cost averaging as a discipline, while averaging down is more selective and reactive.
Real Example: Tesla in 2022–2023
During Tesla’s 65% decline from November 2021 to January 2023, an investor who bought 50 shares at $300 (total $15,000) might have added 30 shares when the price hit $150. The average down calculator would show:
(50 × 300 + 30 × 150) ÷ (50 + 30) = (15,000 + 4,500) ÷ 80 = $243.75.
Without the second purchase, the investor needed a 50% gain just to break even from the $150 low. After averaging, a 62.5% recovery to $243.75 was enough – and by July 2023 the stock crossed $290, putting the compounded position solidly in the green.
Nothing in this article constitutes financial advice. Past performance does not guarantee future results. Always assess your own risk tolerance and seek professional guidance when needed.