Discount Calculator · Practical guide
How to Calculate 20 Percent Off
One shortcut — pay 80% of the sticker — plus a lookup table for the prices you see most.
At a glance
The 20% Off Shortcut
Taking 20% off means you pay 80% of the original price. Multiply the price by 0.80 and you are done: a $50 item costs $40, a $120 item costs $96. If you want the savings instead, multiply by 0.20 — on $50 you save $10.
Interactive tool
Discount Calculator
Enter your own values, then compare the result with the examples below.
Discount Result
Worked Example
A jacket is priced at $89.99 with 20% off. The discount is $89.99 × 0.20 = $18.00 saved, so the final price is $89.99 − $18.00 = $71.99. The calculator above does both steps at once and also shows the savings as a dollar amount.
20% Off Common Prices
| Original Price | You Save | Final Price |
|---|---|---|
| $20.00 | $4.00 | $16.00 |
| $50.00 | $10.00 | $40.00 |
| $80.00 | $16.00 | $64.00 |
| $100.00 | $20.00 | $80.00 |
| $150.00 | $30.00 | $120.00 |
| $250.00 | $50.00 | $200.00 |
Mental Math Tricks
- Find 10% by moving the decimal one place left ($89.99 → about $9), then double it for 20% (about $18 off).
- For quick estimates, round the price first: 20% off $89.99 is close enough to 20% off $90, or $72.
- Remember the order: sales tax is applied to the discounted price, not the original, so your real total is a little lower than taxing the sticker price.
Frequently Asked Questions
What is 20 percent off $100?
Twenty percent of $100 is $20, so you pay $80. For any round number, drop the last digit to get 10% and double it.
Is 20% off the same as paying 80%?
Yes, exactly. Multiplying the original price by 0.80 gives the same final price as subtracting 20% of it — it is just faster.
How do I calculate 20% off with tax?
Apply the discount first, then the tax. A $100 item at 20% off with 8% tax costs $80 × 1.08 = $86.40, not $100 × 1.08 − $20.
Is 20% off a good discount?
It depends on the item's normal price. A genuine 20% off a rarely-discounted brand is strong; 20% off an inflated list price may be no deal at all. Compare the final price across retailers.