What is 20% of 80?
The answer is 16.
Result Explanation
20% of 80 = 16. Because 20% is one fifth, you can also do 80 ÷ 5 = 16. If you mean 20% off 80, then 16 is the discount and the new total is 64 (use the discount calculator for before/after).
If you’re comparing two values (not taking a slice of one number), use the percentage change calculator. For reverse problems like “80 is 20% of what?”, use the reverse percentage calculator.
Why Sixteen Matches Double Forty
Eighty factorises as 2⁴ × 5. Removing one factor of five for twenty percent leaves 2⁴ = 16. That is the same as doubling the eighth you get from forty’s fifth—two independent stories converging on one till-friendly integer.
If you frame eighty as eight ten-pound chunks, each loses two pounds at twenty percent, and 2 × 8 = 16 total discount—another way to see the same sixteen without touching a decimal key.
Mental Maths Shortcuts for 20% of 80
Fastest: 80 ÷ 5 = 16.
- 10% of 80 = 8; double → 20% = 16.
- Double 20% of 40 (8) → 16.
From 25% of 80 = 20, subtract 5% of 80 = 4 to return to sixteen—useful if quarters anchor your head first.
Real-World Examples
Example 1: Twenty percent off an £80 gadget
The saving is £16 and you pay £64 if no other promos stack.
Example 2: Workshop materials
A £80 kit budget with 20% held for spares sets aside £16, leaving £64 for core items if finance applies the rule literally.
Example 3: Tip on an £80 dinner
A twenty-percent gratuity line is £16 on that subtotal; the “new total” only becomes £96 if you add the tip back on, not when the question asked only for the percentage of eighty.
Example 4: Tenfold row
20% of 800 is 160. If a sheet shows 16 or 1600 for that scaled cell, check the percent-to-decimal step.
Common Mistakes
- Quoting £64 when asked only for twenty percent of £80—sixty-four is after the discount.
- Multiplying 20 × 80 without dividing by a hundred → 1600.
- Confusing 20% of 80 with “80 is 20% of what?” (80 ÷ 0.2 = 400).
- Using 80 ÷ 20 as a percentage shortcut—it is not the fifth.
- Treating 0.2% of eighty as twenty percent.
Related Links
FAQ
What is 20% of 80?
20% of 80 is 16.
How do you calculate 20% of 80?
Multiply 80 by 0.2, divide 80 by 5, or double 10% of 80 (8 → 16).
What is 20% off 80?
20% off 80 is a reduction of 16, leaving 64.