Financial

Cost Basis / Average Down Calculator

Blended average cost after adding to a position.

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Inputs

$
$

Result

New average cost

$40.00

Total shares200
Total cost basis$8,000.00
Savings vs old average20.00%

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Short answer

Blended average cost after adding to a position.

What is the Cost Basis / Average Down Calculator?

Blended average cost after adding to a position.

How does the Cost Basis / Average Down Calculator work?

Enter the inputs above and read the result.

Formula

AvgCost = (S1×P1 + S2×P2) ÷ (S1+S2)

Variables

  • S,PShares and price of each lot

Explanation

Averaging down lowers the breakeven price when buying more shares at a lower price.

Examples

Applications

    Advantages

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            Related concepts

            The Cost Basis / Average Down Calculator sits inside the Finance Calculators hub, in the investing & retirement cluster. Growing capital and planning for withdrawal. Understanding the terms below makes the output easier to interpret and easier to compare against neighbouring measures.

            compound growthasset allocationwithdrawal rateyielddividend reinvestmentrisk-adjusted return

            Practical use cases and industry applications

            Understanding Cost Basis / Average Down

            Blended average cost after adding to a position. Within finance calculators, cost basis / average down belongs to the investing & retirement cluster, where it shares terminology and assumptions with closely related tools.

            Learning how cost basis / average down is calculated

            Averaging down lowers the breakeven price when buying more shares at a lower price. Working through the variables one at a time — S,P — makes the result reproducible by hand and easier to sanity-check.

            Using cost basis / average down to make a decision

            Because outputs depend on the assumptions you enter, run more than one scenario before committing to a figure.

            How cost basis / average down compares with related measures

            compound growth, asset allocation, withdrawal rate, yield all describe adjacent aspects of investing & retirement. Comparing this calculator's output against those measures — using the related tools listed on this page — prevents a single metric from being read in isolation.

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