How to Calculate a Tip — Quick Methods That Actually Work

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Method 1: The 10% Double Method (Best for 20%)

This is the fastest mental math approach in existence:

1. Move the decimal one place to the left. $48.50 becomes $4.85. That's 10%.
2. Double it. $4.85 × 2 = $9.70. That's 20%.

If the service was average, use that number. If great, round up. If below average, stay closer to 15%.

Method 2: The Half-Add Method (Best for 15%)

1. Find 10% (move decimal left). On $52: that's $5.20.
2. Take half of that. Half of $5.20 is $2.60.
3. Add them together. $5.20 + $2.60 = $7.80. That's 15%.

Method 3: The Double-Tax Trick

In US states with ~8% sales tax, doubling the tax amount on your receipt gives you a 16% tip — close enough to 18% for most situations. Just look at the tax line and double it. Easy, fast, and leaves a reasonable tip.

Common Tip Quick Reference

• How much is a 15% tip?
• How much is a 20% tip?
• How much is a 10% tip?