Percentage Calculator - All-in-One Tool
Calculate percentages, percentage changes, discounts, tips, and more with our comprehensive percentage calculator. Perfect for business, finance, shopping, and everyday math needs.
Basic Percentage
Result:
0.00
% of = 0.00
Quick Reference
Common Percentage Conversions
Key Formulas
(Value × Percentage) ÷ 100
((New - Old) ÷ Old) × 100
(Part ÷ Total) × 100
Quick Tips
• To find 10%: Move decimal point one place left
• To find 1%: Move decimal point two places left
• For 15%: Calculate 10% + 5% (half of 10%)
• For 20%: Calculate 10% × 2
• Double-check: All percentages should add to 100%
Understanding Percentages
Real-World Applications
Finance: Interest rates, investment returns, loan calculations, and tax computations all rely heavily on percentage calculations.
Business: Profit margins, growth rates, market share analysis, and performance metrics are expressed as percentages.
Shopping: Discounts, sales tax, tips, and price comparisons require percentage calculations for smart purchasing decisions.
Statistics: Survey results, probability, and data analysis frequently use percentages to communicate findings clearly.
Common Mistakes to Avoid
Base Confusion: Always identify the correct base value. "50% more than 100" equals 150, not 50.
Percentage Points: Don't confuse percentage points with percentages. Going from 10% to 15% is a 5 percentage point increase, but a 50% relative increase.
Compound Changes: Sequential percentage changes don't add up. A 10% increase followed by a 10% decrease doesn't return to the original value.
Rounding Errors: Be careful with rounding in multi-step calculations. Keep extra decimal places until the final result.