百分比計算器
計算百分比、求 Y 的 X%,或計算百分比變化。
What is X% of Y?
What is % of = —
X is what % of Y?
is what % of = — %
Percentage change from X to Y
From to = — %
How to use
- Choose the calculation you need: X% of Y, X is what % of Y, or percentage change.
- Enter the numbers in the inline input fields next to each formula.
- The result updates automatically as you type — no button needed.
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- Loan Calculator — compute monthly payments and total interest
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Common percentage use cases
- Discount Calculator — find sale price after a percentage off
- Tip Percentage Calculator — tip math for any bill amount
常見問題
- Is this percentage calculator free?
- Yes, completely free with no account required. All calculations run instantly in your browser.
- Does it work on mobile?
- Yes. The tool is mobile-first and works in Safari and Chrome on iOS and Android.
- What is the formula for percentage change?
- Percentage change = (New Value − Old Value) ÷ |Old Value| × 100. A positive result means an increase; negative means a decrease. For example, going from 80 to 100 is a 25% increase.
- How do I calculate what % X is of Y?
- Divide X by Y and multiply by 100. For example, 30 is what % of 150? → (30 ÷ 150) × 100 = 20%. The second calculator mode does this automatically.
Last updated: By jarvisbox