How to Calculate a Tip
Master tip calculation with our step-by-step guide. Learn quick mental math tricks, avoid common mistakes, and tip with confidence.
💡Quick Answer
To calculate a 20% tip: multiply your bill by 0.20, or use the quick trick—divide the bill by 5. For example, on a $50 bill: $50 ÷ 5 = $10 tip. For 15%, divide by 10, then add half. For 18%, move the decimal left one place and double it minus 10%.
Method 1: The Standard Percentage Method
This is the most accurate method and works for any tip percentage. Here's how to do it:
Step 1: Find the Pre-Tax Subtotal
Look at your bill and find the subtotal before tax. This is the amount you should tip on. Tipping on the pre-tax amount is the professional standard and what servers expect.
Step 2: Convert Percentage to Decimal
Divide your desired tip percentage by 100 to convert it to a decimal:
- 15% = 0.15
- 18% = 0.18
- 20% = 0.20
- 25% = 0.25
Step 3: Multiply Bill × Decimal
Multiply your bill amount by the decimal. For example, for a 20% tip on $50:$50 × 0.20 = $10
Step 4: Add Tip to Bill
Add the tip amount to your original bill to get the total you'll pay:$50 (bill) + $10 (tip) = $60 (total)
Method 2: Quick Mental Math Tricks
No calculator? No problem! Use these mental math shortcuts:
⚡ 20% Tip (Easiest)
Divide by 5
Example: $50 ÷ 5 = $10
Example: $75 ÷ 5 = $15
💡 15% Tip
Find 10%, then add half
Example: $40 → 10% = $4 → half = $2 → $4 + $2 = $6
🎯 18% Tip
Move decimal left, double it, minus 10%
Example: $50 → $5.00 × 2 = $10 → $10 - $1 = $9
🌟 25% Tip
Divide by 4
Example: $60 ÷ 4 = $15
Example: $80 ÷ 4 = $20
💪 The Universal 10% Trick
To find 10% of any number, just move the decimal point one place to the left. This is your building block for calculating any tip percentage!
- $45.00 → 10% = $4.50
- $87.50 → 10% = $8.75
- $123.00 → 10% = $12.30
Method 3: Use a Tip Calculator (Recommended)
The easiest and most accurate way to calculate tips is with a dedicated tip calculator. TipWhiz handles the math instantly, shows you exactly how much to tip, and even splits bills among groups.
Try it now — free calculator below:
Tip Calculator
Enter your bill details below to calculate tips and split costs
Scan Receipt
Upload a photo of your receipt to automatically extract the bill amount
Privacy First: All processing happens on your device. Your receipt images are never uploaded to our servers.
Drag & drop a receipt image
or click to browse files
Tips for better results:
- • Ensure good lighting and avoid shadows
- • Place receipt on a flat, contrasting surface
- • Make sure all text is visible and in focus
- • Align the receipt straight with the camera
Enter the total bill amount including tax
Enter tax amount to tip on pre-tax total (recommended)
Tip Calculation
Tip Percentage: 18%
Split Between People
✨ Why use TipWhiz?
- ✓Instant calculations — no math required
- ✓Tax handling — automatically tips on pre-tax amount
- ✓Bill splitting — divide the bill and tip equally
- ✓Material Design 3 — beautiful, fast, works offline
Real-World Examples
Casual Dinner
Good service, friendly waiter
Fine Dining
Excellent service, attentive staff
Coffee Shop
Counter service, quick order
Group Meal (4 people)
Large group, split evenly
Common Mistakes to Avoid
❌Tipping on the after-tax total
Why it's wrong: This inflates your tip by 7-10% depending on local tax rates
✓ Solution: Always tip on the pre-tax subtotal unless you specifically want to tip more
❌Forgetting to tip on alcoholic drinks
Why it's wrong: Servers work just as hard to bring you drinks as they do food
✓ Solution: Tip on your entire bill including drinks, or tip bartenders separately
❌Assuming auto-gratuity is optional
Why it's wrong: Many restaurants automatically add 18-20% for large groups (6+)
✓ Solution: Check your bill carefully—if gratuity is included, you're done!
❌Tipping the same for takeout as dine-in
Why it's wrong: Takeout requires less service than table service
✓ Solution: Tip 10% for takeout, 15-20% for dine-in service
❌Not adjusting for discounts/coupons
Why it's wrong: Servers provided full service regardless of your discount
✓ Solution: Tip on the original bill amount before discounts were applied
Pro Tips for Perfect Tipping
Round up generously
If your tip calculates to $7.23, round up to $8. It's easier and shows appreciation.
Save your go-to percentages
Bookmark TipWhiz on your phone for instant access whenever you dine out.
Split bills fairly
When splitting with friends, calculate the total with tip first, then divide—not the other way around.
Tip in cash when possible
Cash tips often reach servers faster than credit card tips.
20% is the new standard
In 2025, 20% is considered the baseline for good service in most US cities.
Keep the receipt
Always keep your receipt with the tip amount noted for your records.
Quick FAQ
Q: What's the easiest way to calculate a 20% tip?
A: Divide your bill by 5. For example: $50 ÷ 5 = $10 tip.
Q: Should I tip before or after tax?
A: Always tip on the pre-tax subtotal. It's the professional standard and what servers expect.
Q: How do I calculate a 15% tip in my head?
A: Find 10% by moving the decimal left, then add half of that. Example: $40 → 10% = $4 → half = $2 → $6 total.
Q: Is 15% still acceptable for tips?
A: 15% is acceptable for adequate service, but 18-20% is now the standard for good service.
Q: What if I can't do the math?
A: Use TipWhiz! It's free, instant, and always accurate. Just enter your bill amount and tap the percentage.
🎯 Key Takeaways
- ✓20% tip: Divide bill by 5 (easiest mental math)
- ✓15% tip: Find 10%, add half of it
- ✓Always tip on pre-tax subtotal, not the total with tax
- ✓Use TipWhiz for instant, accurate calculations every time
- ✓When in doubt, round up—generosity is always appreciated
📚 Related Resources
Free Tip Calculator
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Tipping FAQ
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Complete Tipping Guide
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Tipping by Country
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Tip Calculator with Tax
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Restaurant Calculator
Specialized calculator for dining