How is the new average cost calculated?

New average = (existing shares × current average + new shares × purchase price) ÷ total shares. It is a simple weighted average of what you paid.

Does averaging down work for crypto or forex too?

Yes — the maths is identical for any asset: units and unit prices instead of shares. Use the same formula with coins or lots.

Is averaging down a good strategy?

It lowers your breakeven but increases the capital at risk in one position. It works when the original thesis is intact and the price fall is noise; it compounds losses when the thesis is broken.

Can I use this to average up?

Yes — enter a purchase price above your current average and the tool shows the higher blended average. Position traders adding to winners use it the same way.

How do multiple purchases work?

Run the calculation once per purchase, feeding the previous result in as the current position — the average after each buy becomes the starting average for the next.

Does this account for taxes or wash sales?

No — it computes the raw average cost. Tax lots, wash-sale adjustments and fees are jurisdiction-specific and need your broker's records.

Stocks & Investing

Stock Average Down Calculator

Calculate your new average cost per share after buying more stock at a different price — total shares, total cost and the move needed to break even.

Averaging down is buying more of an existing position at a lower price, which reduces the average cost per share and the price move needed to break even.

New average cost

$45.00

Total shares: 200
Total cost: $9,000.00
Average cost change: -$5.00
Breakeven from purchase price: +12.5%

Fees and taxes are not included; add commissions to the total cost for an exact basis.

Worked example

An investor holds 100 shares at a $50 average. The stock drops to $40 and they buy 100 more.

Total shares: 100 + 100 = 200
Total cost: (100 × $50) + (100 × $40) = $9,000
New average cost: $9,000 ÷ 200 = $45
Breakeven from $40: $45 ÷ $40 − 1 = +12.5%

The average cost falls from $50 to $45. From the current $40 price, the stock now needs a 12.5% rise to break even — versus 25% if no extra shares had been bought.

How this is calculated

The new average is the cost-weighted mean of the existing position and the new purchase:

newAverage = (shares × avgCost + newShares × newPrice) ÷ totalShares

The breakeven figure divides the new average by the purchase price: newAverage ÷ newPrice − 1 — the percentage rise the stock needs from where you just bought for the whole position to break even.

The same formula averages up when the purchase price is above the current average — useful for adding to winners with a known new breakeven.

When to use this calculator

Use this before adding to a losing position, so the decision is made on numbers rather than hope: the exact new average cost, and how much smaller the required recovery becomes. Knowing the breakeven move from the current price is the honest measure of what the add-on buys you.

It works just as well for averaging up. Position traders adding to winners can see how much the blended cost rises and how much cushion the position keeps above it.

Use it also for planned accumulation: if you intend to build a position in tranches, entering each planned tranche shows the average cost you would lock in at each stage of the plan.

Common mistakes

Averaging down on a thesis that has broken — a lower average cost doesn't fix a losing investment, it concentrates more capital in it.
Confusing the average cost with the breakeven after fees — commissions and spreads sit on top of the blended average.
Ignoring position-size limits: repeated averaging can quietly turn one holding into an outsized share of the portfolio.

Frequently asked questions

How is the new average cost calculated?: New average = (existing shares × current average + new shares × purchase price) ÷ total shares. It is a simple weighted average of what you paid.
Does averaging down work for crypto or forex too?: Yes — the maths is identical for any asset: units and unit prices instead of shares. Use the same formula with coins or lots.
Is averaging down a good strategy?: It lowers your breakeven but increases the capital at risk in one position. It works when the original thesis is intact and the price fall is noise; it compounds losses when the thesis is broken.
Can I use this to average up?: Yes — enter a purchase price above your current average and the tool shows the higher blended average. Position traders adding to winners use it the same way.
How do multiple purchases work?: Run the calculation once per purchase, feeding the previous result in as the current position — the average after each buy becomes the starting average for the next.
Does this account for taxes or wash sales?: No — it computes the raw average cost. Tax lots, wash-sale adjustments and fees are jurisdiction-specific and need your broker's records.