Calculate percent of a number, percent increase, percent decrease, percentage difference, and reverse percentage. Live results for USA and UK.
Percentages are one of the most universally used mathematical concepts in everyday life. From calculating a tip at a restaurant to working out a discount during a sale, from understanding your pay rise to computing VAT on a UK purchase or sales tax in the US — percentages are everywhere. This free percentage calculator handles five different types of percentage calculations instantly, with live results as you type.
Whether you are a student learning the fundamentals, a shopper checking discount savings, a business owner calculating margins, or a professional working with financial data, this tool gives you accurate answers in seconds along with the step-by-step working so you understand how the result was reached.
This is the most basic percentage calculation. You want to find a specific percentage of a given number. The formula is simple:
Result = (Percentage / 100) × Number
Example: What is 15% of 200? Answer: (15 / 100) × 200 = 30
Real-world uses: calculating a 20% tip on a $50 restaurant bill ($10), finding 20% VAT on a £150 product (£30), or working out a 25% deposit on a $400,000 house ($100,000).
A percentage increase tells you by how much a value has grown, expressed as a percentage of the original value.
New Value = Original × (1 + Percentage / 100)
Example: A salary of $50,000 increases by 8%: $50,000 × 1.08 = $54,000
Common uses include salary raises, investment growth, price inflation, and rent increases.
The opposite of percentage increase — how much a value falls, expressed as a percentage of the original.
New Value = Original × (1 - Percentage / 100)
Example: A £200 jacket is 30% off: £200 × 0.70 = £140
Used constantly in retail discounts, depreciation calculations, and price reductions.
This mode calculates what percentage one number is of another, or the percentage change between two values.
Percentage = (Value A / Value B) × 100
Example: 45 is what percent of 180? (45 / 180) × 100 = 25%
Useful for comparing scores, budgets, market shares, and ratios.
Given a final value and the percentage that was applied, work backwards to find the original amount.
Original = Final Value / (1 + Percentage / 100) (for an increase)
Original = Final Value / (1 - Percentage / 100) (for a decrease)
Example: A price after 20% VAT is £120. What was the pre-VAT price? £120 / 1.20 = £100
| Calculation Type | Formula | Example |
|---|---|---|
| % of a number | (% / 100) × Number | 15% of 200 = 30 |
| % increase | Original × (1 + %/100) | $100 + 10% = $110 |
| % decrease | Original × (1 − %/100) | $100 − 20% = $80 |
| A is what % of B | (A / B) × 100 | 25 is 50% of 50 |
| Reverse % (from increase) | Final / (1 + %/100) | £120 ÷ 1.20 = £100 |
| Reverse % (from decrease) | Final / (1 − %/100) | £80 ÷ 0.80 = £100 |
In the United Kingdom, Value Added Tax (VAT) is charged at the standard rate of 20% on most goods and services. There is also a reduced rate of 5% (applied to domestic energy bills, children's car seats, and certain other items) and a zero rate (0%) for food, children's clothing, and books.
When you see a price listed as "ex-VAT" or "+VAT", you need to add 20% to find the consumer price. Conversely, if you see a VAT-inclusive price and want the net amount, divide by 1.20 (reverse percentage). For example, a B2B invoice for £500 ex-VAT becomes £600 including VAT at 20%.
| Net Amount (ex-VAT) | VAT (20%) | Gross Amount (inc-VAT) |
|---|---|---|
| £50 | £10 | £60 |
| £200 | £40 | £240 |
| £1,000 | £200 | £1,200 |
| £5,500 | £1,100 | £6,600 |
In the United States, sales tax is applied at the state and local level rather than nationally. Rates vary widely — from 0% in states like Oregon, Montana, New Hampshire, Delaware, and Alaska, to over 10% in some localities when state and local taxes are combined. The average combined US sales tax rate is approximately 6.6%.
| State | State Sales Tax Rate | Notes |
|---|---|---|
| California | 7.25% | Plus local taxes up to ~10.75% |
| New York | 4.00% | NYC total ~8.875% |
| Texas | 6.25% | Local adds up to 8.25% |
| Florida | 6.00% | No state income tax |
| Oregon | 0% | No sales tax |
In the US, a standard tip is 15–20% of the pre-tax bill at restaurants, 15–18% for taxis, and $1–2 per bag for hotel staff. In the UK, tipping is less structured — 10–12.5% at restaurants is common, though many add a service charge automatically. Our percentage calculator makes quick work of any tip amount: simply set the percentage and enter the bill total.
Retailers in both the US and UK frequently advertise percentage discounts. A "30% off" sign means you pay 70% of the original price. To find the sale price: Sale Price = Original × (1 − Discount% / 100). To find how much you save: Savings = Original × (Discount% / 100). Our discount mode calculates both instantly.
When negotiating a raise, percentage increase is the standard metric. A £40,000 salary with a 5% rise becomes £42,000. A $75,000 salary with a 7.5% raise becomes $80,625. Use the percentage increase mode to quickly check what any raise percentage actually means in cash terms — and use the reverse percentage to calculate what percentage increase gets you from your current salary to your target salary.
Students commonly need to calculate their percentage score on tests and exams. If you score 72 out of 90 marks, your percentage is (72 / 90) × 100 = 80%. The percentage difference mode handles this directly. For US letter grades: A = 90–100%, B = 80–89%, C = 70–79%, D = 60–69%, F = below 60%. UK university grades typically classify a First as 70%+, 2:1 as 60–69%, 2:2 as 50–59%, and a Third as 40–49%.
Percentage change is the standard way to express investment performance. If a stock was bought at $120 and is now worth $156, the percentage gain is ((156 − 120) / 120) × 100 = 30%. If a property purchased for £280,000 is now worth £320,000, the capital gain percentage is ((320,000 − 280,000) / 280,000) × 100 = 14.3%.
Inflation is expressed as a percentage increase in the general price level. If inflation is 5% and your salary stays flat, your real purchasing power decreases by approximately 5%. If you receive a 3% pay rise during 5% inflation, your real wage has decreased by roughly 2%. Understanding these percentage relationships is essential for financial planning.
These two terms are often confused. Percentage change is directional — it measures how much a specific value increased or decreased from a starting point to an ending point. Percentage difference compares two values without implying direction, often using the average of the two as the denominator.
For most practical purposes (retail, finance, salary), percentage change is what you need. Percentage difference (using average) is more common in scientific and statistical contexts where neither value is clearly the "base."
Divide the first number by the second number, then multiply by 100. For example, 45 is what percent of 150? (45 ÷ 150) × 100 = 30%. Use the "% Difference" mode on this calculator.
To add 20% VAT: multiply the net price by 1.20. To remove VAT from a VAT-inclusive price: divide by 1.20. For example, £240 ÷ 1.20 = £200 net. Use the reverse percentage mode for this calculation.
Percentage Increase = ((New Value − Old Value) / Old Value) × 100. If a price rises from $80 to $100, the increase is ((100 − 80) / 80) × 100 = 25%.
Multiply the bill total by 0.15. On a $60 bill: $60 × 0.15 = $9 tip. Or use the "% of Number" mode: enter 15 as the percentage and 60 as the number.
A reverse percentage finds the original value before a percentage was applied. If a price after a 25% discount is $75, the original was $75 ÷ 0.75 = $100. Use the reverse % mode on this calculator.
New Value = Original × (1 − %/100). For a 20% decrease on $500: $500 × 0.80 = $400. The decrease amount itself is $500 × 0.20 = $100.
The US national average combined state and local sales tax rate is approximately 6.6%, but it varies hugely by location — from 0% in Oregon and New Hampshire to over 10% in parts of Louisiana, Tennessee, and Arkansas.
A percentage point is an absolute difference between two percentages. If approval ratings go from 40% to 45%, that is a 5 percentage point increase, but a 12.5% increase in relative terms. Always clarify which you mean in financial or political contexts.
Results are estimates for educational purposes only. Tax rates, VAT rules, and financial regulations change frequently and vary by jurisdiction. Always verify with official sources or a qualified professional before making financial decisions.
Percentage increase = (New − Old) ÷ Old × 100. On a salary rise from $50,000 to $55,000: (55000 − 50000) ÷ 50000 × 100 = 10% rise. Use this for salary rises, stock gains, rent hikes, or any "how much more" comparison. Our calculator shows the working so you can check results manually.
Percentage decrease = (Old − New) ÷ Old × 100. On a jacket reduced from £80 to £60: (80 − 60) ÷ 80 × 100 = 25% off. This is the formula behind every sale sign and the one most people mentally approximate incorrectly. Always divide by the original (old) value, not the new one.
After a discount, what was the original price? If you paid £40 after a 20% discount, the original was £40 ÷ 0.80 = £50. Not £48 (a common mistake). Our reverse percentage mode handles this for any discount amount — essential for sale-shopping and for verifying retailer advertised discounts.
To find what percentage one number is of another: (Part ÷ Whole) × 100. What percent is 8 of 50? (8 ÷ 50) × 100 = 16%. Useful for test scores ("I got 38 out of 50 — what grade?"), polling ("1,200 of 3,500 agreed — what percent?"), and batting averages alike.
Percentage change = (New − Old) ÷ Old × 100. Positive for increase, negative for decrease. A stock going from $100 to $130 is +30%. From $130 back to $100 is −23% (not −30% — because you are dividing by a larger starting number). This asymmetry is why investing percentages require care.
(Percentage ÷ 100) × Number. Example: 20% of 80 = (20 ÷ 100) × 80 = 16.
After a 20% discount, divide the sale price by 0.80 to get the original. £40 ÷ 0.80 = £50.
Points is the raw difference (4% → 6% = 2 points). Percentage is the relative change (4% → 6% = 50% increase).
(X ÷ Y) × 100. Example: 8 out of 50 = (8 ÷ 50) × 100 = 16%.
Because each percentage is applied to a different base. Start at 100, +50% = 150, −50% = 75. Net result: −25%.