Percent calculator

Never get stuck on a percentage problem again. Calculate the fraction of a number, find out what percentage one value represents of another, determine the original base value, calculate an increase or decrease, or calculate VAT. This calculator gives you the exact answer with just one click – including the formula and calculation steps.

What is a percentage? – Explained simply

A percentage is simply a way to express a number as a fraction of 100. The word comes from the Latin “pro centum”—literally “out of one hundred.” So, when you see 30%, it simply means 30 out of 100.

Every calculation here is essentially the same idea from a different perspective: a share (30% of 200), a percentage (30 is what percentage of 200), a base value (30 is 15% of what?), an increase or decrease, or a value plus taxes. Simply select your calculation type above, enter your numbers, and get your answer.

How to use the calculator

1. Select your calculation method from the dropdown menu – share, percentage, base value, increase/decrease or value added tax (VAT).
2. Enter your two known values.
3. Click on Calculate.
4. Get your answer, including the formula and step-by-step calculation.

Common percentage calculations

Calculate a percentage of a number (proportion)

This is the calculation most people encounter when they Google “what is 20 percent of 50” or “how to calculate a percentage of a price.” You already know the total value and the percentage—you just want to know what that percentage actually is. The Percentage Calculator X% of Y gives you the exact amount with just one click.

Also searched as: “calculate the percentage of a number”, “what is X% of Y”, “calculate the percentage amount”.

Examples:

• How to give the right tip in a restaurant – “20 percent tip on a bill of 45 euros”
• Taxes and commissions – “VAT on an 80-euro item”, “6 percent commission on a sale of 15,000 euros”
• Adjusting ingredients in a recipe – “How much is 25 percent more flour than 200 g?”
• Calculating exam points – “What is 75 percent of 80 points?”
• Discounts, memberships and rewards – “30 percent discount on 90 euros”, “15 percent discount on a 40-euro gym membership”, “10 percent discount with customer card on 65 euros”, “5 percent cashback on a 200-euro purchase”
• Adjust dosages or mixtures – “10 percent of 500 ml solution”

Ready to calculate your own value? Use the percentage calculator above – simply select “Find a Percentage of a Number” from the dropdown menu.

Finding out what percentage one number is of another

This option is for when you already have two numbers and want to know their ratio – the classic “X to Y” question, which people search for as “what percentage is X of Y” or “convert fraction to percentage”. The calculator “W is what % of G” provides you with the percentage instantly.

Also searched as: “X of Y in percent”, “convert points to percent”, “calculate ratio in percent”.

Examples:

• Converting a test result into a grade – “72 out of 90 as a percentage”
• Check how much of a budget has been spent – “340 out of 500 euros budget in percent”
• Calculate an attendance or completion rate – “22 out of 30 days as a percentage”
• How to correctly interpret survey or voting results – “45 out of 300 people in percent”
• Understanding election results – “1,200 out of 5,000 votes in percent”
• Calculating the win rate in sports – “9 out of 12 games won as a percentage”
• Everyday measurements – “43 out of 100 as percent”, “3 out of 8 liters”, “50g sugar out of 400g total amount”

Finding the original base value (working backwards)

Sometimes you know the share and the percentage, but not the whole from which it originates – this is reverse calculation, often searched for as “X is Y percent of what number” or “find the original price before discount”. The calculator W is P% of what calculates backward to the total amount.

Also known as: “Original Price Calculator”, “Reverse Percentage Calculator”, “Find the Whole from One Part”.

Examples:

• Determining the price of a product before a sale – “A discount of 42 euros corresponded to 30 percent; what was the original price?”
• Determining the total amount of a down payment – “A down payment of 8,000 euros was equivalent to 20 percent; what is the total amount?”
• Deriving total quantities from a sample – “12 items represent 25 percent of the stock”, “45 people were 15 percent of the participants”
• Working backwards on a bill or receipt – “6 euros tip was 10 percent, what was the bill?”, “After a 15 percent discount, 68 euros were paid, what was the original price?”
• Finding the full price behind a voucher code – “Saved 25 euros with a 20 percent voucher; what was the price?”

Increase or decrease a number by a percentage

This covers both directions – adding a percentage to a number (a surcharge, a salary increase, a price increase) or subtracting a percentage (a discount, a price reduction). Frequently searched terms include “add 15 percent to 200” or “20 percent discount calculator”. The calculator X plus P% / X minus P% instantly provides the new value.

Other common search queries: “percent discount calculator”, “add percentage to a number” and “surcharge and discount calculator”.

Examples:

• Add fees and surcharges – “12 percent service fee on 60 euros”, “7 percent delivery fee on 50 euros” and “15 percent markup on the wholesale price”
• Set a goal for weight loss or gain – “Lose 5 percent of 80 kg”
• Shopping discounts and price reductions – “20 percent discount on a 120-euro jacket”, “40 percent discount in the Black Friday sale”, “An additional 10 percent discount on an already reduced price”
• Recurring fee increases – “Monthly fee increased by 8 percent”, “School fees increased by 6 percent”

Find the percentage change between two numbers

You already know the initial and final values – now you want to know the percentage difference, either upwards or downwards. This is expressed as “percentage change from X to Y” or “by what percentage did the price increase?”. The calculator “From X to Y, what % change?” displays the exact percentage change.

Also searched as: “Percentage increase or decrease calculator”, “Compare two numbers as percentages”, “Growth rate calculator”.

Examples:

• Tracking a rent or membership fee increase year-on-year – “The rent rose from 800 to 850 euros, percentage increase.”
• Tracking weight changes over time – “Got from 80 kg to 74 kg; percentage loss”
• Price changes – “Petrol rose from 1.50 to 1.80”, “one price changed from 50 to 65 euros”, “electricity bill rose from 60 to 75 euros”
• Tracking population or employee development – “The population increased from 20,000 to 21,500; percentage change.”
• Growth figures – “Followers increased from 1,000 to 1,500” and “Downloads increased from 500 to 800”

Calculate value added tax (VAT)

A specific but frequently searched calculation – either adding VAT to a net price to obtain the final amount, or subtracting the VAT already included in a price. Searched for as “VAT calculator net to gross” or “how much VAT is included in this price”. The VAT calculator clearly displays net, VAT, and gross amounts together.

Related search queries: “Add VAT to price”, “Remove VAT from price”, “Net-Gross VAT calculator”.

Examples:

• Adding VAT to a net price for an invoice – “Add 19 percent VAT to a net price of 100 euros”
• Calculating the VAT already included in a receipt – “How much VAT is in a gross price of 238 euros?”
• Invoicing as a freelancer or small business – “Calculating VAT on service invoices”
• Checking the VAT portion of a restaurant bill – “Is VAT included in the €45 restaurant bill?”
• Calculate import VAT for an online order – “VAT on a 60-euro online order”
• Comparison of net and gross prices – “Net vs. Gross when shopping abroad”, “Converting a net offer into a price including VAT for a customer”

Percentage calculation using the rule of three

The rule of three solves problems where you know three values and need to find a fourth – like “If you earn €120 for 8 hours, how much do you earn for 5 hours?” Percentages work the same way, except one of the values is always fixed at 100. The calculator “P% of G, W is what % of G, W is P% of what” solves each of these problems instantly.

Examples:

• “What is 20 percent of 90 euros?” → 18 euros
• “20 percent tip on a bill of 45 euros — how much is that?” → 9 euros
• “72 out of 90 — what percentage is that?” → 80%
• “45 euros is 30 percent of what number?” → 150 euros
• “I paid 68 euros after a 15 percent discount — what was the original price?” → 80 euros
• “Add 19 percent VAT to a price of 100 euros — what is the total?” → 119 euros

Try out your own numbers – open the calculator and get the answer plus the complete calculation steps.

The formulas behind the percentage calculator

Formula 1: What is P% of G? (Calculate the proportion)

Formula 2: What percentage is X of Y? (Calculate the percentage)

Formula 3: X is P% of what? (Calculate the base value)

Formula 4: Increase by X% (add the percentages)

Formula 5: Reduction by X% (subtract percentage)

Formula 6: Percentage change

Formula 7: Calculating Value Added Tax (VAT)

Net → Gross: Net price + (Net price × VAT rate ÷ 100) = Gross price

Gross → Net: Gross price ÷ (1 + VAT rate ÷ 100) = Net price

A practical example: From discount to checkout

Let’s look at how these formulas work together in a real-world scenario.

Sarah sees a jacket that originally cost €120, but is now reduced by 20%.

• Step 1 – Calculate the selling price (acceptance formula): Original price − (original price × percentage ÷ 100) = New value 120 € − (120 € × 20 ÷ 100) = 120 € − 24 € = 96 €
• Step 2 – Add 19% VAT to the sales price (VAT formula): Net price + (Net price × VAT rate ÷ 100) = Gross price 96 € + (96 € × 19 ÷ 100) = 96 € + 18.24 € = 114.24 €

  Sarah pays €114.24 at the checkout.

• Step 3 – Later she checks how much she has saved (percentage formula):

  What percentage of the original €120 did she save?

  (X ÷ Y) × 100 = P% (€24 ÷ €120) × 100 = 20% ✓

  Confirm the discount!

• Step 4 – A friend asks for the price before VAT (gross to net): Gross price ÷ (1 + VAT rate ÷ 100) = Net price €114.24 ÷ 1.19 = €96 ✓

  This matches step 1.

• Step 5 – Six months later, the same jacket costs €108. What is the percentage change compared to the price of €114.24? ((New value − Old value) ÷ Old value) × 100 = Percentage change ((108 € − 114.24 €) ÷ 114.24 €) × 100 = −5.46 % (price decrease)

Would you like to run your own numbers through a scenario like Sarah's? Try the calculator – it automatically performs each of the steps mentioned above.

Percentage calculations work everywhere – with all currencies

Good news: Percentage calculations are currency-independent. Whether euros, dollars, pounds or rupees – the formula remains the same.

The universal formula:
(Percentage ÷ 100) × Amount = Result

Examples with different currencies:

• In Euros: 20% of 100 Euros = 20 Euros
• In US dollars: 20% of =
• In British pounds: 20% of £100 = £20
• In Indian Rupees: 20% of 100 = 20

Percentages, decimals and fractions – conversion table

Quick conversions at a glance:

Why percentage calculations are more important than you think

Price tags, payslips, bank statements, headlines – percentages are everywhere. That's precisely why “percent calculator” is one of the most frequently searched terms. People usually don't want the formula, but the concrete result.

Here's where percentage calculations play a role in everyday life:

• Shopping — comparing “20% discount” vs. “30% discount on the second item”, whether in Euros, Dollars or Pounds.
• Money — “4.5% savings interest”, “12% effective annual interest rate”, “€85 tax deducted” — you only know if that’s good or bad when you calculate the actual amount.
• News — “Unemployment rises by 2 percentage points”, “Inflation at 3.4%”, “Survey shows 45% approval” – numbers mean little if you cannot distinguish percentage points from percentages or check the calculation yourself.
• The classic trap — A 20% salary increase followed by a 20% cut will not get you back to zero!

Common mistakes in percentage calculations

• Adding 20% and then subtracting 20% does not return you to the starting value.
  €100 + 20% = €120. Subtracting 20% from €120 gives you €96—not €100.
• A “percentage point” and a “percent” are not the same thing.
  If an interest rate rises from 5% to 7%, that's an increase of 2 percentage points. But relative to the original 5%, it's a percentage increase of a whopping 40%.
• Two consecutive discounts are smaller than you might think.
  If something is already 20% off and there's another 10% discount, that 10% is deducted from the already reduced price – not the original price.
• “20% of 90” and “20% discount on 90” are two different things.
  20% of €90 is the net amount: €18. A 20% discount on €90 means the new price after the discount: €72.
• Deducting VAT doesn't simply mean subtracting the percentage.
  If a price already includes 19% VAT, you can't just subtract 19%. You have to divide by 1.19 instead.

FAQs (Frequently Asked Questions)

1. How do I find out the original price before a discount?

Divide the reduced price by (1 − discount as a decimal).
Formula: Reduced price ÷ (1 − discount% ÷ 100) = Original price.
Example: You paid €68 after a 15% discount → 68 ÷ 0.85 = €80.

2. How do you calculate two consecutive discounts?

Apply the first discount and then subtract the second discount from the new, already reduced price – not from the original price.
Example: A €100 item with a 20% discount and an additional 10% discount: €100 → €80 → €72. (Not €70, which would result from directly adding the percentages.)

3. Can a percentage be negative, and what does that mean?

Yes – a negative percentage represents a decrease.
Example: -10% means a reduction of 10%; -50% means that the value has halved.

4. How do you convert a percentage into a decimal or a fraction?

To divide a decimal, divide by 100; to divide a fraction, write the number over 100 and simplify it.
Example: 75% = 0.75 = 3/4.

5. How do you calculate the percentage growth over several years (compound interest)?

Multiply the initial value by (1 + interest rate)^number of periods.
Example: €1,000 growing by 5% annually for 3 years → 1000 × (1.05)³ ≈ €1,157.63.

6. How is the percentage error calculated?

Subtract the actual value from the estimated value, divide by the actual value, and multiply by 100.
Formula: ((Estimated − Actual) ÷ Actual) × 100 = Percentage Error

7. What is the rule of three and how does it relate to percentages?

It's a method for finding an unknown value when three related values are known, by establishing a ratio – percentages are just one version where one side is fixed at 100.
Example: If 8 hours earn €120, how much do 5 hours earn? (120 ÷ 8) × 5 = €75.

Related calculators and tools

• Calculator for percentage increase – calculate growth and increases
• Calculator for percentage decrease – determine declines and reductions
• Percentage change calculator – compare values over time
• Decimal to Percent Converter – Convert decimal numbers to percentages
• Percent to Decimal Converter – Convert percentages to decimals
• Fraction to Percent Converter – Easily convert fractions to percentages
• Percent to Fraction Converter – Convert percentages to fractions
• Fraction calculator – For all types of fraction calculations

Last updated: July 30, 2026