Target Average Price Calculator

How Many Shares Do I Need to Buy to Average Down?

Work backwards from the average price you want to the exact quantity and budget you need.

What this calculator does

A regular average down calculator answers "if I buy this much, what will my average be?" This one answers the reverse: "how much do I need to buy to get my average down to X?"
Set the average price you're aiming for, such as a level where you'd break even on a modest rebound, and see the exact quantity and cash it takes. You can also compare several possible buy prices side by side to find what fits your budget.

How to use it

Current position: Enter your current average price and the quantity you hold.
Target average price: Enter the average price you want to end up with.
Buy price: Enter the price you'll buy at, either the current market price or your planned limit price.
Results: Press "Calculate" to see the quantity and cash needed, plus your total position afterwards.
Keep in mind: The buy price must be below your target average, and the target must be below your current average.

Examples

"My average is $180. How many shares at $120 to get it down to $150?"

Holding: 10 shares at $180 / Target average: $150
Buy price: $120
You need to buy 10 more shares
Cost: $1,200 (total position: 20 shares, $3,000)

"My BTC average is $100,000. How much at $60,000 to reach an $80,000 average?"

Holding: 0.1 BTC at $100,000 / Target average: $80,000
Buy price: $60,000
You need to buy 0.1 BTC more
Cost: $6,000 (total position: 0.2 BTC, $16,000)

Stocks ($) Crypto / Decimals

1. Current position

Current average price

Quantity held

2. Your target

Target average price

Buy price (current market price)

Not sure which price fits your budget? Enter a few candidate buy prices and compare them at once. Your current average, quantity and target from above are used.

Buy price	Qty needed	Cost	Total invested

Sorted from lowest to highest cost.

Target Average Price Result

Additional buy needed to reach your target average

Quantity

Cost

Total invested afterwards

Total quantity afterwards

Results are estimates based on your inputs. Fees, tick sizes and rounding can change the exact numbers. If you can only buy whole shares, round the quantity up to make sure you reach your target. For reference only, not investment advice.

Target Average Price Calculator FAQ

A regular average down calculator tells you what your average will be after a buy you've already decided on. This calculator works backwards: you choose the average price you want, and it tells you how much you need to buy to get there.
It's built for planning a specific exit or break-even level and knowing the exact budget it requires.

It solves the average price equation for the quantity you need to buy:
Quantity needed = Current quantity × (Current average − Target) ÷ (Target − Buy price)
For example, 10 shares at $180 with a $150 target and a $120 buy price gives 10 × 30 ÷ 30 = 10 shares.

There are two cases where the math can't work. First, if your buy price is at or above the target, buying more can only pull your average toward the buy price, never below it. Second, if your target is above your current average, you'd be averaging up, which this calculator isn't designed for.
Adjust the numbers so that buy price < target < current average.

If you're buying right now, use the current market price (the ask). If you plan to wait for a support level, enter the price where you'd place your limit order.
The lower the buy price, the fewer shares you need to reach the same target. Use the comparison tool to see that trade-off across several prices at once.

The calculator shows the exact mathematical quantity. If your broker only allows whole shares, round up to the next share so you're sure to reach the target. Crypto and fractional-share accounts can buy the exact amount.

That's a useful answer in itself: it tells you the target is unrealistic for your budget. Try a higher target average or a lower buy price and recalculate.
The goal is to find a balance between the average you want and the cash you can afford to commit without over-concentrating your portfolio in one position.