Percentage Calculator

What Is a Percentage?

A percentage is a way of expressing a number as a fraction of 100. The word comes from the Latin per centum, meaning "by the hundred." In everyday finance and crypto trading, percentages appear everywhere: price movements are quoted as percentage changes, portfolio allocations are expressed as percentage weights, and yields are described as annual percentage rates. Mastering percentage calculations is therefore one of the most practical skills a crypto investor can develop.

There are five core percentage operations, and this calculator handles all of them simultaneously using just three inputs — Value A, Value B, and a Percentage figure — so you can read off any result without switching tools.

How to Calculate Percentage Change for Crypto Gains and Losses

Percentage change is the most important calculation for any crypto trader. It tells you how much a price has moved relative to its starting point, expressed as a percentage. The formula is:

% Change = ((Value B − Value A) / |Value A|) × 100

Enter your entry price as Value A and the current or exit price as Value B. If the result is positive, the price increased; if negative, it fell. For example, if you bought Bitcoin at $40,000 and it rose to $44,000, the percentage change is ((44,000 − 40,000) / 40,000) × 100 = +10%. If it dropped to $36,000 instead, the result would be −10%, confirming a 10% loss.

This formula is identical to simple ROI when you make a single purchase. For portfolios with multiple buys at different prices, sum your total cost basis and use our dedicated ROI calculator for a more complete picture.

The Five Percentage Formulas Explained

• X% of Value A (percentOf): Multiplies Value A by the percentage. Formula: (Percent / 100) × Value A. Use this to find a target level — for example, 25% of a $200 position is $50, which could represent a take-profit tier.
• Value A as % of Value B (whatPercent): Divides Value A by Value B and multiplies by 100. Formula: (Value A / Value B) × 100. Useful for comparing your position size to a portfolio total or benchmark.
• % Change from A to B (percentChange): The standard price-change formula above. Positive means appreciation; negative means depreciation.
• Increase by X% (increase): Applies the percentage as an upward multiplier. Formula: Value A × (1 + Percent / 100). Use this to project a price target — for example, Value A at $200 increased by 25% gives $250.
• Decrease by X% (decrease): Applies the percentage as a downward multiplier. Formula: Value A × (1 − Percent / 100). Use this to calculate a stop-loss level — for example, $200 decreased by 25% gives $150.

Worked Example: Tracking an Altcoin Move

Suppose you bought Solana at $120 (Value A = 120) and it is now trading at $156 (Value B = 156). You also want to know what happens if it moves another 30% from here (Percent = 30). The calculator outputs all five results at once:

• 30% of $120 = $36 — a useful reference for partial take-profit sizes.
• $120 as % of $156 = 76.92% — your entry was at roughly 77% of the current price.
• % Change (120 → 156) = +30% — you are currently up 30%.
• $120 increased by 30% = $156 — confirms that a 30% move from entry equals today's price.
• $120 decreased by 30% = $84 — a potential stop-loss level if the trade reverses.

This single set of inputs answers multiple trading questions simultaneously, making it far more efficient than running separate calculations for each scenario.

Practical Tips for Crypto Traders

Use percentage change to compare across assets. Absolute dollar moves are misleading when comparing a $50,000 Bitcoin position to a $2,000 Ethereum holding. Percentage change normalizes the comparison. A coin that gains $500 from a $2,000 base outperforms one that gains $2,000 from a $50,000 base.

Set stop-losses and targets in percentages, not dollars. Saying "I will exit if the price drops 15%" is a rule you can apply consistently across positions of different sizes. Use the decrease formula to convert that percentage rule into a concrete price level before you enter the trade.

Watch out for asymmetric percentage moves. A 50% loss requires a 100% gain to break even, not a 50% gain. This asymmetry is one of the most underappreciated facts in crypto risk management. Use the increase formula to see exactly how much recovery a drawdown requires.

Combine with live price data for real-time decisions. Services like smartmoneyapi.com provide live crypto price feeds that you can use to populate Value A and Value B directly, turning this calculator into a real-time percentage monitor for any coin pair without manual data entry.

Verify DeFi yield claims. When a protocol advertises an APY of 200%, use the increase formula to sanity-check the projection: a $1,000 principal increased by 200% gives $3,000 — a 3x return in one year. While such rates do occur in early DeFi liquidity mining, they are rarely sustainable. Treat them as a starting point for deeper due diligence, not a guarantee.