📈 Stock & Crypto Average Down Calculator
A stock average calculator for your average entry price across every buy lot — the price a holding must reach to break even, before fees and tax.
Stock & Crypto Purchase Orders
This is a simple average entry price, not an IRS cost basis figure. The average-cost method is only permitted for mutual fund/RIC and dividend-reinvestment shares (26 CFR 1.1012-1(e)); individual stock and crypto lots require FIFO or specific-identification accounting for tax reporting.
What Stock & Crypto Average Down Calculator Does
This calculator finds your average entry price across every purchase lot you enter — the single per-share number you would need the price to return to just to break even, before fees or taxes. Add a shares-and-price row for each buy, and it divides total dollars spent by total units held.
The math treats a stock share and a fraction of a cryptocurrency the same way: a quantity and a price paid for it. There is no unit or currency selector, so every row you enter is assumed to be the same instrument in the same currency — mixing a USD stock lot with a EUR-priced one, or two different tickers, in the same table produces a number that means nothing.
The result is now labeled "Average Entry Price Per Share (Breakeven)" rather than "cost basis," and that wording change matters. Under federal tax regulations, the average-cost method is only a permitted way to report gain or loss for a narrow set of holdings — mutual fund and other regulated-investment-company (RIC) shares, and shares acquired through a dividend reinvestment plan (DRIP). An individual stock position or a cryptocurrency lot has to be reported using FIFO or specific-lot identification instead. The tables and worked examples below show exactly how different those two numbers can get on the same set of trades.
How to Use Stock & Crypto Average Down Calculator
- Add each buy order with its number of shares and purchase price
- Click + Add Purchase Lot to record subsequent dip purchases
- Instantly view your total shares, total invested capital, and weighted average price per share
Formula Used by Stock & Crypto Average Down Calculator
Weighted average entry price
Average price = Σ(shares_i × price_i) ÷ Σ shares_i
- shares_i
- Quantity bought in purchase lot i
- price_i
- Price paid per unit in purchase lot i
- Σ(shares_i × price_i)
- Total dollars invested across every lot — the "Total Cost" the tool displays
- Σ shares_i
- Total units held across every lot — the "Total Position" the tool displays
Worked example
The tool's own default two lots: 100 shares bought at $150, then 50 shares bought at $120.
- Lot 1 cost: 100 × $150 = $15,000
- Lot 2 cost: 50 × $120 = $6,000
- Total shares: 100 + 50 = 150
- Total invested: $15,000 + $6,000 = $21,000
- Average = $21,000 ÷ 150
Result: $140.00 per share on a 150-share position that cost $21,000 total — the exact figures shown when the calculator loads.
Reverse solve: shares needed to reach a target average
x = N × (T − P) ÷ (Q − T)
- N
- Shares already held
- P
- Current average price per share
- Q
- Price of the new purchase (must be below T for x to be positive)
- T
- Target average price after the new purchase, between Q and P
- x
- Additional shares needed at price Q to reach the target average T
Worked example
You hold 150 shares at a $140.00 average (the result above) and want to pull the average down to $130.00 by buying more at $100.
- x = 150 × (130 − 140) ÷ (100 − 130)
- x = 150 × (−10) ÷ (−30) = 1,500 ÷ 30 = 50
- Check: new total shares = 150 + 50 = 200
- Check: new total cost = (150 × 140) + (50 × 100) = 21,000 + 5,000 = 26,000
- Check: new average = 26,000 ÷ 200 = 130.00 — matches the target
Result: Buying 50 more shares at $100 brings a 200-share position to exactly $130.00 average. This calculator has no target-average input — it only totals the lots you enter — so the way to use this formula with the tool is to compute x here first, then add it as a trial lot and confirm the displayed average matches.
Average entry price vs. FIFO cost basis on a partial sale
Gain or loss = (Sale price − Basis per share) × Shares sold
- Basis per share (average method)
- The single blended figure this tool reports across all lots
- Basis per share (FIFO)
- The price of the specific oldest lot, which is a broker's default identification method absent other instructions
Worked example
Three lots of 100 shares each, bought at $50, $70 and $90 (average: $70.00 on 300 shares costing $21,000 total, per the formula above). Now sell 100 shares at $65.
- Average method: (65 − 70) × 100 = −$500
- FIFO: the first 100 shares acquired were the $50 lot, so (65 − 50) × 100 = +$1,500
- Difference between the two results: $1,500 − (−$500) = $2,000
Result: The same sale reads as a $500 loss under the simple average and a $1,500 gain under FIFO — a $2,000 swing from identical trade data. This calculator only ever computes the average-method figure; it has no sell input and cannot produce the FIFO number itself.
Who the Average-Cost Method Is Actually Allowed For
Confirmed against the regulation text at 26 CFR 1.1012-1(e)(1)(i). Anything outside these two categories defaults to FIFO or specific-lot identification under IRS Publication 550.
| Holding | Average-cost method allowed for tax reporting? | Method required instead |
|---|---|---|
| Mutual fund / RIC shares held with a custodian | Yes — 26 CFR 1.1012-1(e)(1)(i) | N/A — average-cost is a permitted election |
| Dividend reinvestment plan (DRIP) shares acquired after Dec. 31, 2010 | Yes — 26 CFR 1.1012-1(e)(1)(i) and (e)(6) | N/A — average-cost is a permitted election |
| Individual stock bought directly (not through a DRIP) | No | Broker's default (typically FIFO) or specific-lot identification |
| Cryptocurrency and other digital assets | No — not "stock" as defined in 1.1012-1(e) | FIFO or specific-lot identification |
Shares Needed to Average Down From $140.00, Buying at $100
Starting position: 150 shares at a $140.00 average — the calculator's own default example. Computed with x = N(T−P)÷(Q−T) and verified by re-averaging the resulting position.
| Target average | Additional shares needed at $100 | New total shares | Reduction from $140.00 |
|---|---|---|---|
| $135.00 | 21.43 | 171.43 | 3.57% |
| $130.00 | 50.00 | 200.00 | 7.14% |
| $125.00 | 90.00 | 240.00 | 10.71% |
| $120.00 | 150.00 | 300.00 | 14.29% |
What a Split Does to the Same Position (150 shares, $140.00 average, $21,000.00 total cost)
A split multiplies share count and divides average price by the same ratio; total cost never changes. Verified: $21,000.00 ÷ new share count in each row.
| Split ratio | New share count | New average price | Total cost |
|---|---|---|---|
| No split (as purchased) | 150 | $140.00 | $21,000.00 |
| 2-for-1 | 300 | $70.00 | $21,000.00 |
| 3-for-1 | 450 | $46.67 | $21,000.00 |
| 4-for-1 | 600 | $35.00 | $21,000.00 |
How to Read Your Result
This is a breakeven price, not a tax cost basis
The $500-loss-versus-$1,500-gain example above is not a rounding quirk — it is two different accounting methods giving opposite signs on the same trade. 26 CFR 1.1012-1(e)(1)(i) restricts the average-cost election to mutual fund/RIC shares and DRIP shares. An individual stock lot or a cryptocurrency purchase has to be reported to the IRS using FIFO or a specific lot you identify at the time of sale, per IRS Publication 550. Use this tool to see where your breakeven sits; use your broker's 1099-B or your own lot records for what you actually owe tax on.
Averaging down gets more expensive than it feels
The reverse table above shows the pattern: pulling a $140.00 average down to $120.00 — a 14.29% reduction — required buying 150 additional shares at $100, a price 28.57% below the original average, on top of the 150 already held. That is a 100% increase in share count to move the average by roughly a seventh. The lower the new price relative to the average, the fewer new shares are needed; the closer the new price sits to the existing average, the more shares it takes to move it at all.
A split or DRIP purchase is just another lot, entered correctly
A 2-for-1 split turns the 150-share, $140.00-average position into 300 shares at $70.00, with the $21,000.00 total cost unchanged — the split table above shows the same effect at 3-for-1 and 4-for-1 ratios. This calculator does not detect or apply a split automatically; after one happens, edit the affected lot's share count and price yourself to match. A DRIP reinvestment is simpler: enter it as an ordinary new lot at the reinvestment price, since a DRIP purchase is one of the two categories in the table above where the resulting average is actually the number the IRS lets you report.
Buying back into a stock you sold at a loss can trigger a wash sale
Averaging down commonly means adding to a position you already own — but if you sold shares of that same security at a loss anywhere else in your accounts within the 30 days before or after the new purchase, IRC §1091 disallows that loss for tax purposes. The window runs 30 days before the sale through 30 days after it, 61 days in total. This calculator has no wash-sale check; it only totals the lots you give it.
Limitations & Accuracy Notes
- Models buy lots only. There is no way to record a sale, so it cannot compute realized gain or loss, remaining share count after a partial exit, or a post-sale average — it only ever reports the average across every lot currently entered.
- Total cost excludes commissions, exchange fees, network/gas fees and bid-ask spread. A crypto purchase with a taker fee, or a brokerage ticket with a flat commission, has a true cost per unit higher than what this tool reports.
- No FIFO, LIFO, or specific-lot identification. The single average this tool computes is not the cost basis the IRS expects for an individual stock or crypto lot — see the eligibility table above.
- No wash-sale detection. Adding a lot here never checks whether the same security was sold at a loss elsewhere in the last 30 days.
- No currency selector. Every entry is treated as the same unit and currency; mixing tickers or currencies in one table silently produces a meaningless average.
- Negative and non-numeric share or price entries are clamped to zero rather than rejected, so a mistyped negative number becomes a zero-share, zero-cost lot instead of raising an error.
- Stock splits are not detected or applied automatically. After a real split, the affected lot has to be edited by hand to reflect the new share count and price.
Frequently Asked Questions
What is averaging down in stock investing?
How is weighted average cost per share calculated?
What does averaging down actually do?
Does a lower average price mean I am in profit?
How is dollar-cost averaging different?
Should commissions be included?
Does this account for dividends or stock splits?
Is this investment advice?
References & Further Reading
- 26 CFR 1.1012-1(e) — Basis of property; election to use average basis method — Paragraph (e)(1)(i) restricts the average-cost election to RIC/mutual-fund shares and DRIP shares acquired after Dec. 31, 2010
- IRS Publication 550 — Investment Income and Expenses — Default (FIFO) and specific-identification rules for basis of securities sold, and the wash-sale discussion
- 26 U.S.C. § 1091 — Wash sales of stock or securities (Cornell Legal Information Institute) — Defines the 30-days-before/30-days-after window during which a repurchase disallows a realized loss