Bitcoin cost basis calculator
See your average Bitcoin cost basis, current portfolio value, and unrealized gain or loss from any list of past purchases.
Learn about our methodology →
Methodology
We verify every formula against primary sources, run it on live data, and document each model's assumptions and limits.
Learn about our methodology →
Built and reviewed by Fabio Arcieri
Fabio Arcieri
Founder, Orange Abacus
Bitcoin researcher with a background in economics and a decade in digital marketing. He builds and reviews every calculator on this site against primary sources.
Read full profile →Last reviewed: July 2026
How to use this calculator
Add one row per Bitcoin purchase. Enter each lot in whichever unit you remember.
- Amount — the fiat value or the BTC quantity of a single purchase.
- Date — the day you made that purchase.
How to read the output
The widget turns your lots into a single position summary.
- Unrealized gain or loss — the difference between your portfolio’s current value and what you invested, in fiat and as a percentage.
- Current portfolio value — your total BTC holdings valued at the live price.
- Total invested — the sum of fiat spent across every lot you entered.
- Bitcoin accumulated — the total BTC across all lots, in whichever direction each lot was entered.
- Average cost basis — your total invested divided by your total BTC, the average price you paid per coin.
Why your cost basis matters
Your average cost basis is the number your unrealized gain or loss is measured against. Without it, “up” or “down” has no reference point beyond the current price, which tells you nothing about your own entries. Average cost basis condenses every purchase, at every price, into one figure you can compare against the live BTC price at a glance.
Buying at scattered prices over time changes that average with each new lot. A purchase below your current average pulls it down; a purchase above pushes it up. Recalculating after each new buy keeps the figure current and keeps your read on the position grounded in what you actually paid, not in memory or approximation.
Frequently asked questions
What is cost basis in Bitcoin?
Cost basis in Bitcoin is the amount you paid to acquire your BTC, expressed in fiat currency. Across multiple purchases at different prices, the average cost basis is your total fiat invested divided by your total BTC accumulated. It is the reference point for measuring gain or loss against the current price, separate from any tax treatment applied to it.How do I calculate my average Bitcoin cost basis?
Add up the fiat value of every purchase, then divide by the total BTC you hold. This calculator does that automatically: enter each lot as either a fiat amount or a BTC amount with its purchase date, and it derives the counterpart from the historical daily close for that date, then computes the weighted average across all lots.Does this calculator account for FIFO, LIFO, or HIFO accounting methods?
No. This calculator uses a simple weighted average (total fiat invested divided by total BTC held) and does not apply FIFO, LIFO, HIFO, or any other tax-lot accounting method. Jurisdictions differ on which method applies to capital gains, so tax-lot selection is outside the scope of this tool.What price data does the calculator use for past purchases?
Historical BTC prices come from a bundled CryptoCompare dataset of daily closes, covering July 17, 2010 to today. When you enter a fiat amount for a given date, the calculator looks up that day's close to derive the BTC purchased, and vice versa when you enter a BTC amount.Can I track purchases in both USD and EUR?
Yes. A currency toggle at the top of the widget switches the display between USD and EUR. EUR values use European Central Bank exchange rates, cached for 24 hours, applied on top of the USD-denominated historical BTC prices.