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Percent Off Calculator (“X% off”)

Calculate “X% off” online — free and step by step. See how much you save and pay, or work the original price back from the discounted price.

Quick answer
How much is X% off?
At X% off, the saving is price · X ÷ 100 and you pay the rest. Example: 30% off $120 is 120 · 30 ÷ 100 = $36 saved, so you pay $84. The other way around: if you know the price paid and the discount rate, the original price is paid ÷ (1 − X ÷ 100) — $84 after 30% off gives 84 ÷ 0.7 = $120.
The tool

Enter values — get full working

How much do you save and what do you pay?
Comma or dot as decimal separator, negative values allowed.
Step-by-step
Press Calculate to see every step.
HowTo

How to calculate “X% off” — step by step

Using “30% off $120” — savings and the price you pay
  1. 1
    Step 1 of 4

    Set the price and discount rate

    Note the original price and the discount in percent. Example: $120 original price, 30% off.

  2. 2
    Step 2 of 4

    Compute the saving

    Multiply the price by the discount rate and divide by 100: 120 · 30 ÷ 100 = 3600 ÷ 100 = $36. That's how much you save.

  3. 3
    Step 3 of 4

    Find the price to pay

    Subtract the saving: $120 − $36 = $84. Or use the remaining factor directly: 120 · 0.7 = $84.

  4. 4
    Step 4 of 4

    Optional: recover the original price

    If you only know the price paid, divide by the remaining factor: 84 ÷ (1 − 30 ÷ 100) = 84 ÷ 0.7 = $120.

Examples

“X% off” — worked examples

Savings, amount due, and reverse calculation with the full working
30% off $120
120 · 30 ÷ 100 = 36
120 − 36
save $36, pay $84
50% off $60
60 · 50 ÷ 100 = 30
60 − 30
save $30, pay $30
20% off $45
45 · 20 ÷ 100 = 9
45 − 9
save $9, pay $36
$84 after 30% off
84 ÷ (1 − 0.3)
84 ÷ 0.7
original $120
$30 after 50% off
30 ÷ 0.5
original $60
$75 after 25% off
75 ÷ 0.75
original $100
Theory

What does “X% off” mean?

“X% off” describes a percentage reduction off a price. Two questions are typical. First, forward: how much do you save and what do you pay? The saving is price · X ÷ 100, and the price to pay is price − saving, that is price · (1 − X ÷ 100). The factor (1 − X ÷ 100) is the remaining factor: at 30% off it is 0.7, so you pay 70% of the price. Second, backward: you only know the price paid and want the original. Since the price paid is (1 − X ÷ 100) of the original, you divide it by exactly that factor: original = paid ÷ (1 − X ÷ 100). $84 after 30% off gives 84 ÷ 0.7 = $120. This reverse calculation is handy for reconstructing the list price from a sale price or comparing two offers fairly. Note: at 100% off the remaining factor would be 0 — you cannot work backward, because any original price would map to $0.

Pitfalls

Common mistakes

Reversing with + instead of ÷

You don't recover the original by adding the discount back (84 · 1.3 = 109.20 ≠ 120). Divide by the remaining factor: 84 ÷ 0.7 = 120.

Reading the saving as the amount due

At 30% off $120 the saving is $36 and you pay $84. Don't swap the two.

Wrong remaining factor

At 30% off you pay 70%, so the factor is 0.7 — not 0.3. The factor is always 1 minus the discount share.

Assuming percentage points

“30% off” means 30% of the price, not 30 cents or 30 units. It is always a share of the original price.
FAQ

Frequently asked questions about “X% off”

Glossary

Glossary — key terms explained simply

X% off
A reduction of X percent on the price.
Saving
The amount saved: price · X ÷ 100.
Remaining factor
(1 − X ÷ 100). The share of the price you still pay.
Original price
The list price before the discount (100%).
Amount due
The price after the discount is taken off.
Reverse calculation
Going from the price paid back to the original: ÷ remaining factor.