A cryptocurrency market cap calculator is a tool that calculates the total market value of a cryptocurrency by multiplying its current price by its circulating supply. Our WhatIf calculator goes further by showing what price one crypto would have if it matched another asset's market cap.

Market cap is calculated using the formula: Market Cap = Current Price × Circulating Supply. For example, Bitcoin's market cap of $1.4 trillion (as of 2026) equals approximately $68,000 × 21 million BTC in circulation.

If Bitcoin had Ethereum's market cap (approximately $250 billion), the price of one BTC would drop to around $12,000 - representing a significant decrease from current levels. This demonstrates how market cap reflects both price and supply.

Comparing market caps helps investors understand the relative value and potential of different cryptocurrencies. A coin with a higher market cap is typically more established, while a lower market cap coin might have higher growth potential but also higher risk.

Market cap represents the total value of all coins in circulation, but not the total invested capital. It's calculated as price × supply. Unlike stock market caps, crypto market caps can be more volatile due to price fluctuations and token unlocks.