Percentage Calculator

Calculate percentages instantly, find X% of Y, percentage change, and more. Free to use.

Free to use. Runs in your browser.

Instantly calculate X% of Y, percentage change, or add/subtract percentages.

Four calculation modes, all browser-based.

What is X% of Y?

% of

X is what % of Y?

is what % of

Percentage Change

From

→

Add / Subtract %

±%

What Percentages Actually Are

"Percent" comes from the Latin per centum, per hundred. When you say "25%," you mean 25 out of every 100. That's it. Every percentage problem boils down to dividing something into 100 equal parts and counting how many you're talking about.

This simplicity is why percentages show up everywhere: tax rates, exam scores, battery levels, interest rates, sale prices, tip amounts, nutritional labels, loan terms, weather forecasts. They're the universal language for "how much of the whole."

The four calculations above cover every percentage problem you'll encounter in daily life. "What is X% of Y" handles discounts and tips. "X is what % of Y" handles grades and proportions. Percentage change handles price movements and growth. Add/subtract percentage handles VAT and markups.

The Three Percentage Formulas You Need

Every percentage problem in existence is one of these three. Once you know which one you're dealing with, the maths is straightforward.

Find the part

Part = Whole × (% ÷ 100)

"What is 15% of £80?"

£80 × 0.15 = £12

Use for: discounts, tips, tax amounts, commission

Find the percentage

% = (Part ÷ Whole) × 100

"42 out of 60 is what %?"

(42 ÷ 60) × 100 = 70%

Use for: exam scores, proportions, market share

Find the whole

Whole = Part ÷ (% ÷ 100)

"£36 is 20% of what?"

£36 ÷ 0.20 = £180

Use for: working backwards from VAT, finding original prices

Mental Maths Shortcuts

To Find	Shortcut	Example
10%	Move the decimal one place left	10% of £85 = £8.50
5%	Find 10%, then halve it	5% of £85 = £4.25
15%	Find 10% + 5%	15% of £85 = £8.50 + £4.25 = £12.75
20%	Find 10%, then double it	20% of £85 = £17.00 (the VAT shortcut)
25%	Divide by 4	25% of £85 = £21.25
33%	Divide by 3	33% of £85 ≈ £28.33
50%	Halve the number	50% of £85 = £42.50
1%	Move the decimal two places left	1% of £85 = £0.85
Any %	Flip the numbers: X% of Y = Y% of X	8% of 25 = 25% of 8 = 2 (much easier!)

The flip trick is magic. 8% of 25 sounds hard. 25% of 8 is obviously 2. They're the same answer. This works because multiplication is commutative: 0.08 × 25 = 0.25 × 8. Next time you're stuck, flip the numbers and see if one direction is easier.

Real-World Percentage Reference

Percentages you'll actually encounter in life, from tax rates to tip customs to business margins. Search for what you need.

Context	Percentage	Formula	Example
UK VAT (standard)	20%	Price × 1.20	£100 item costs £120 with VAT. To remove VAT from £120: £120 ÷ 1.20 = £100
UK VAT (reduced)	5%	Price × 1.05	Home energy, child car seats, sanitary products
US sales tax (avg)	5-10%	Price × 1.05 to 1.10	Varies by state: Oregon 0%, California 7.25%, Tennessee 9.55%
UAE VAT	5%	Price × 1.05	Introduced 2018. Applies to most goods and services
German VAT (MwSt)	19%	Price × 1.19	Reduced rate 7% for food, books, public transport
Restaurant tip (UK)	10-12.5%	Bill × 0.125	Check if service charge is already included before adding more
Restaurant tip (US)	18-22%	Bill × 0.20	20% is standard for good service. 15% for basic. Never below 15%
Restaurant tip (Japan)	0%	Don't tip	Tipping is considered rude in Japan, good service is the default
UK income tax (basic)	20%	Income × 0.20	On income from £12,571 to £50,270 (2025/26)
UK income tax (higher)	40%	Income × 0.40	On income from £50,271 to £125,140 (2025/26)
UK National Insurance	8%	Earnings × 0.08	Class 1 employee rate on earnings £12,570-£50,270
Mortgage rate (avg UK)	4-6%	Annual interest on balance	Fixed 2-year deals vary. 1% change on £250K = £2,500/year
Savings interest (avg)	3-5%	Balance × rate	ISA rates vary. £10,000 at 4.5% = £450/year interest
Retail profit margin	25-50%	(Price - Cost) ÷ Price	Item costs £10, sells for £20 = 50% margin
Restaurant food cost	28-35%	Ingredient cost ÷ Menu price	A £15 dish should have £4-5 of ingredients
Recruitment agency fee	15-25%	Salary × rate	£50K salary × 20% = £10,000 placement fee
Estate agent fee (UK)	1-3%	Sale price × rate	£300K house × 1.5% = £4,500 + VAT = £5,400
Credit card interest	18-30% APR	Balance × (rate ÷ 12) monthly	£3,000 at 22% APR = ~£55/month in interest alone
Inflation (UK target)	2%	Prices × 1.02 per year	BoE target. £100 today = £102 next year in theory
Stamp duty (UK, £250K+)	5%	On portion above £250K	Tiered system: 0% to £250K, 5% on £250K-£925K, 10% on £925K+
eBay seller fee	10-13%	Sale price × rate	Final value fee varies by category. Plus PayPal/payment fees
Etsy seller fee	6.5%	Sale price × 0.065	Transaction fee. Plus listing fee (20p) and payment processing (4%+25p)
Battery health (phones)	80-100%	Current capacity ÷ Original	Apple recommends replacement below 80%. Expect ~1% loss per month
Body fat (healthy male)	10-20%	Fat mass ÷ Total mass	Athletes: 6-13%. Essential fat minimum: ~5%
Body fat (healthy female)	18-28%	Fat mass ÷ Total mass	Athletes: 14-20%. Essential fat minimum: ~13%

Showing 25 of 25 entries.

Fraction ↔ Decimal ↔ Percentage

Quick conversion reference. Every fraction has a decimal equivalent, and every decimal can be expressed as a percentage. This table covers the fractions you'll encounter most often.

Fraction	Decimal	Percentage	Mental Maths Tip
1/2	0.5	50%	Half of anything. Move decimal one left and multiply by 5
1/3	0.333...	33.33%	Recurring decimal. For quick mental maths, use 33%
2/3	0.666...	66.67%	Two thirds. Quick check: should be roughly double 1/3
1/4	0.25	25%	Quarter. Divide by 4 or halve twice
3/4	0.75	75%	Three quarters. Find 25% and subtract from whole
1/5	0.2	20%	One fifth. Same as dividing by 5 or finding 10% × 2
2/5	0.4	40%	Two fifths. Double the 1/5 result
3/5	0.6	60%	Three fifths. Triple the 1/5 result
4/5	0.8	80%	Four fifths. Find 1/5 and subtract from whole
1/6	0.1666...	16.67%	Recurring. Roughly halfway between 1/5 (20%) and 1/8 (12.5%)
1/8	0.125	12.5%	One eighth. Half of a quarter. Half of half of half
3/8	0.375	37.5%	Three eighths. 1/8 × 3. Common in cooking measurements
5/8	0.625	62.5%	Five eighths. Slightly more than 3/5 (60%)
7/8	0.875	87.5%	Seven eighths. Almost whole. 100% minus 12.5%
1/10	0.1	10%	One tenth. Just move the decimal point one place left
1/12	0.0833...	8.33%	One month out of a year. Annual ÷ 12 for monthly figures
1/20	0.05	5%	One twentieth. Half of 10%. Common for VAT reduced rate
1/100	0.01	1%	One hundredth. Move decimal two places left. The building block

Percentage Change vs Percentage Points

This trips up even financial professionals. If a mortgage rate goes from 4% to 5%, it rose by 1 percentage point but by 25% in relative terms (because 1 is 25% of 4). Both statements are true, but they mean very different things for your wallet.

Change	Percentage Points	Percentage Change	Why It Matters
Interest rate 2% → 4%	+2 pp	+100%	Your repayments literally doubled
Tax rate 20% → 25%	+5 pp	+25%	You keep less of each pound earned
Inflation 10% → 3%	−7 pp	−70%	Prices still rising, just more slowly
Unemployment 5% → 4%	−1 pp	−20%	20% fewer people are unemployed

What this means for you: When news headlines say "inflation fell 2%," check if they mean 2 percentage points (meaningful) or 2% of the current rate (minor). Politicians and journalists mix these up constantly. The percentage change calculator above gives you the relative change.

Worked Example: Is This Sale Actually a Good Deal?

The situation: A furniture shop advertises: "Bank Holiday Sale! 30% off everything, PLUS an extra 15% off with code SPRING15." You find a sofa originally priced at £1,200. What do you actually pay?

The common mistake

Most people think: 30% + 15% = 45% off. So £1,200 × 0.55 = £660. That would be nice, but it's wrong.

What actually happens

First discount: £1,200 × 0.70 = £840 (30% off). Second discount applied to the ALREADY REDUCED price: £840 × 0.85 = £714 (15% off £840, not £1,200).

The real discount

You pay £714 instead of £1,200. That's a saving of £486, which is 40.5% off, not 45%. The £54 difference between what you expected (£660) and what you pay (£714) is the "stacking tax" that retailers count on you not noticing.

The quick check

To find the combined discount of stacked percentages: multiply the "keep" fractions. You keep 70% × 85% = 59.5%. So you pay 59.5% of the original = £714. Total discount = 40.5%.

Common Percentage Mistakes

Reversing a percentage

If a price rises 20% then falls 20%, you're NOT back where you started. £100 + 20% = £120. Then £120 − 20% = £96. You've lost £4. The base changes after each step, a common trap in investment returns.

Stacking discounts

A 30% discount followed by a 20% discount is NOT 50% off. It's 30% off the original, then 20% off the reduced price. £100 → £70 → £56. You save 44%, not 50%. Use our Discount Calculator to get it right.

Removing VAT incorrectly

To remove 20% VAT, divide by 1.2, do NOT subtract 20%. £120 inc. VAT ÷ 1.2 = £100 net. NOT £120 − 20% = £96. Use our VAT Calculator to avoid this mistake.

Comparing unequal bases

"Company A grew 50% and Company B grew 10%", but if A went from £1M to £1.5M and B from £100M to £110M, B added 20x more actual revenue. Always check the absolute numbers behind percentages.

Confusing markup with margin

A 50% markup and a 50% margin are very different. £100 cost + 50% markup = £150 price. But 50% margin means cost is £75 on a £150 price. Use our Markup Calculator or Margin Calculator.

Percentage of a percentage

"Sales rose 50%, and 30% of that growth came from online." That 30% is 30% of the 50% growth, not 30% of total sales. It means online contributed 15 percentage points of the 50% growth.

Related Calculators

Discount Calculator

Stack multiple sale discounts correctly

VAT Calculator

Add or remove UK/EU/UAE tax correctly

Tip Calculator

Calculate tips and split bills

Profit Margin Calculator

Calculate profit as a percentage of revenue

Markup Calculator

Convert between cost and selling price

ROI Calculator

Calculate return on investment as a percentage

How to use this tool

Choose a calculation mode

Enter your numbers

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Common uses

Calculating sale discounts while shopping
Working out tax amounts on invoices
Comparing price changes over time
Figuring out tip amounts at restaurants
Calculating grade percentages for exams

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Frequently Asked Questions

What percentage calculations are supported?

Four modes: X% of Y, X is what % of Y, percentage change from X to Y, and add/subtract a percentage. These cover every real-world percentage problem, discounts, tips, tax, grades, growth rates, and more.

How is percentage change calculated?

Percentage change = ((New − Old) / |Old|) × 100. A positive result means an increase; negative means a decrease. This formula works for prices, salaries, populations, or any quantity that changes over time.

How do I find what percentage one number is of another?

Divide the part by the whole and multiply by 100. For example, 35 out of 50 = (35 ÷ 50) × 100 = 70%. Use the 'X is what % of Y' mode above for instant results.

What's the difference between percentage change and percentage points?

Percentage points measure the absolute difference between two percentages. Percentage change measures the relative difference. If interest goes from 4% to 5%, that's 1 percentage point but a 25% increase. Headlines often blur this distinction.

How do I calculate a percentage in my head?

Start with 10% (move the decimal left one place) and build from there. 20% = double 10%. 5% = half of 10%. 15% = 10% + 5%. For 1%, move the decimal two places left. You can combine these blocks for any percentage.

How do I reverse a percentage to find the original price?

Divide by (1 + rate). If an item costs £120 after 20% markup, the original was £120 ÷ 1.20 = £100. Do NOT subtract 20% from £120, that gives £96, which is wrong. The base changes after each percentage operation.

Why doesn't adding then subtracting the same percentage return the original?

Because the base changes. £100 + 20% = £120, then £120 − 20% = £96, not £100. The 20% decrease applies to £120 (a larger base), so it removes more than was added. This asymmetry is why investment losses hurt more than equivalent gains help.

How do I calculate percentage increase between two numbers?

Use the formula: ((New − Old) ÷ Old) × 100. If your salary went from £30,000 to £33,000: ((33000 − 30000) ÷ 30000) × 100 = 10% increase. The 'Percentage Change' mode above handles this automatically.

How do I convert between fractions, decimals, and percentages?

Fraction → decimal: divide top by bottom (3/4 = 0.75). Decimal → percentage: multiply by 100 (0.75 = 75%). Percentage → fraction: put over 100 and simplify (75% = 75/100 = 3/4). They're three ways of expressing the same ratio.

Can I calculate compound percentage changes?

Yes, apply each change sequentially using the add/subtract mode. A 10% increase followed by a 10% increase is not 20%, it's 21% (1.10 × 1.10 = 1.21). This is how compound interest works.

How do percentages apply to VAT and sales tax?

To add 20% VAT, multiply by 1.20. To remove it, divide by 1.20. Never subtract 20% from the gross price, that gives the wrong answer. Our VAT Calculator handles this with country-specific rates.

Is this tool free to use?

Yes. It is free to use, and all calculations happen in your browser. Nothing is sent to any server.

Results are for general informational purposes only and should be checked before use. They are not professional advice. See our Disclaimer and Terms of Service.