Average Cost Basis Calculator
Blended cost across three purchase lots — average price, total position and unrealized P&L at today's price.
Formula
Averages are for dashboards; taxes are computed lot-by-lot (FIFO by default in India and the US unless you specify lots). Watch the anchor-to-average bias — your average price is irrelevant to whether the next rupee belongs in this stock.
Not financial advice — for informational and analytical use only. Verify all figures with a qualified professional before acting on them.
Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates — verify with a qualified professional before making decisions. Read the full disclaimer.
Need average cost basis calculator results fast? Analysts, founders, traders and finance professionals use the Average Cost Basis Calculator to skip the spreadsheet and get a defensible answer in one step — free, private and instant.
About Average Cost Basis Calculator
Blended cost across three purchase lots — average price, total position and unrealized P&L at today's price. Averages are for dashboards; taxes are computed lot-by-lot (FIFO by default in India and the US unless you specify lots). Watch the anchor-to-average bias — your average price is irrelevant to whether the next rupee belongs in this stock. The governing relationship is average = Σ(qty × price) / Σ qty. The Average Cost Basis Calculator computes entirely in your browser — free, private (your figures never leave your device) and instant, recalculating live as you change any input.
How to use Average Cost Basis Calculator
- 1Enter Lot 1 — shares, Lot 1 — price (currency), Lot 2 — shares, Lot 2 — price (currency), Lot 3 — shares (0 if none), Lot 3 — price (currency) into the Average Cost Basis Calculator.
- 2The result is computed automatically using average = Σ(qty × price) / Σ qty — there is no button to press.
- 3Change any input to model a different scenario, then copy or share the result.
Why use Average Cost Basis Calculator?
- ✓Computes average cost basis calculator instantly with the correct formula — no spreadsheet needed
- ✓100% free and unlimited, with no sign-up, login or paywall
- ✓Runs entirely in your browser, so the figures you enter stay private
- ✓Shows the formula, a live worked example and references so you can defend the number
Frequently asked questions
What is the formula behind the Average Cost Basis Calculator?+
Average Cost Basis Calculator uses average = Σ(qty × price) / Σ qty. Averages are for dashboards; taxes are computed lot-by-lot (FIFO by default in India and the US unless you specify lots). The tool substitutes your actual inputs into this relationship and shows the worked example step by step.
What inputs does the Average Cost Basis Calculator need?+
Enter Lot 1 — shares, Lot 1 — price (currency), Lot 2 — shares, Lot 2 — price (currency), Lot 3 — shares (0 if none), Lot 3 — price (currency) and the result updates immediately — there is no button to press. Change any value to model a different scenario in real time.
Is the Average Cost Basis Calculator free, and is my data private?+
Yes — it is completely free with no sign-up or usage limit, and it runs entirely in your browser, so the numbers you enter are never uploaded or stored on any server. It is for informational and analytical use, not financial advice.
What should I watch out for when using the Average Cost Basis Calculator?+
Watch the anchor-to-average bias — your average price is irrelevant to whether the next rupee belongs in this stock.
What is the Average Cost Basis Calculator based on?+
The method follows authoritative sources: Brokerage cost-basis reporting standards. The formula and references are shown on the page so you can verify and cite the result.
Related Finance tools
Human Life Value (HLV) Calculator
The economic value of your future earnings to your family — the income-replacement basis for sizing a life-insurance cover.
● LiveTerm Life Insurance Coverage Calculator
How much term-life cover you actually need — replacing income, clearing debts and funding goals, net of existing assets and cover.
● LiveDIME Method Life Insurance Calculator
The DIME formula — Debt + Income + Mortgage + Education — a fast, complete way to size a life-insurance cover.
● Live