AxelBase Calculator

Professional-grade crypto capital gains tracking with a smooth, modern interface.

About the Calculator

Published: December 27, 2025

The Crypto Capital Gains Calculator is a free, open-source, privacy-first web utility designed to help cryptocurrency holders estimate their capital gains taxes using the widely accepted First-In-First-Out (FIFO) cost basis method. Built as a completely client-side static application, it runs entirely in your browser with no data ever leaving your device.

Developed in line with a detailed SRS, the tool focuses on simplicity and accuracy. It categorizes gains into short-term (held less than one year) and long-term (held one year or more), reflecting the most common tax treatment distinction used globally.

Unlike commercial tax software, this tool asks for nothing. There is no tracking, no analytics, and no server-side processing. You input your transactions, and all computations happen instantly on your device. It represents a commitment to privacy, transparency, and education in the cryptocurrency space.

Thank you for using this tool. We hope it helps demystify crypto capital gains taxation.

How to Use

Detailed Instruction Guide

Step 1: Add Your Transactions

For each buy or sell, fill in the Date, Type (Buy/Sell), Quantity, and Price in USD. Use the "+ Add Entry" button to create more rows.

Step 2: Validate and Calculate

Once your logs are entered, click "Calculate Gains". The tool sorts your entries chronologically automatically and matches buys to sells via FIFO.

Step 3: Review Breakdown

Review the generated table. Positive values are profits, while negative values represent capital losses. Holding periods are calculated precisely in days (365+ days = Long-term).

Tips for Best Results:

Use 4 decimal places for high precision.
Include all buys before corresponding sells for accurate matching.
Remember this tool supports one cryptocurrency at a time.

Frequently Asked Questions

What cost basis method is used?

Strict FIFO (First-In-First-Out). Sells are matched to the oldest available buy lots first.

Is my data secure?

Yes. No transaction data or personal info is ever transmitted or stored. It lives only in your browser's memory.

Does it handle losses?

Yes. Losses appear as negative values and are aggregated into your totals for offset analysis.

Is this suitable for official filing?

No. This is an educational estimator. Always consult a tax professional for official reporting.

Visit our blog for in-depth articles on crypto taxation logic.