Finance Percentage Calculators
Calculate interest, ROI, GST, VAT, profit margins, commissions and more — instantly.
Interest Rate Calculator
Simple & Compound interest
Interest = Principal × Rate% × Time Finance Note: Compound interest grows faster than simple interest the longer the time period.
No calculations yet.
Investment Return (ROI) Calculator
Calculate gains and annualized returns
ROI% = ((Final - Initial) / Initial) × 100 Finance Note: A good long-term ROI benchmark is 7–10% annually (S&P 500 historical average).
No calculations yet.
GST Calculator
Goods and Services Tax
Total = Amount × (1 + GST%/100) Finance Note: Common GST rates: Australia 10%, India 5–28%, Canada 5%, New Zealand 15%.
No calculations yet.
VAT Calculator
Value Added Tax
Gross = Net × (1 + VAT%/100) Finance Note: Common VAT rates: UK 20%, EU average 21%, UAE 5%.
No calculations yet.
Profit Margin Calculator
Calculate gross profit, margin and markup
Margin% = ((Revenue - Cost) / Revenue) × 100 Markup% = ((Revenue - Cost) / Cost) × 100 Finance Note: A healthy profit margin varies by industry — retail averages 2–5%, SaaS averages 60–80%.
No calculations yet.
Commission Calculator
Calculate sales commissions and total pay
Commission = Sale Amount × Rate% Finance Note: Average sales commission rates range from 5–10% depending on industry.
No calculations yet.
Compound Interest Calculator
Detailed compounding with annual breakdown
A = P × (1 + r/n)^(n×t) Finance Note: Daily compounding earns slightly more than annual compounding on the same rate.
| Year | Interest | Balance |
|---|
No calculations yet.
How to Calculate Interest Rate Percentage
Calculating interest is a fundamental skill for managing personal and business finances. Simple interest is straightforward: multiply your principal by the annual rate and the number of years. For example, $1,000 at 5% for 3 years earns $150 ($1,000 × 0.05 × 3). However, most modern financial products like savings accounts and loans use compound interest.
Compound interest is "interest on interest." It means your earnings are reinvested to earn even more in the next period. The frequency of compounding—whether daily, monthly, or annually—can significantly impact your final balance. Our interest rate calculator and compound interest tool handle these complex formulas for you, providing a clear breakdown of how your money grows over time.
Understanding ROI, Profit Margin, and Markup
For investors and business owners, understanding the difference between ROI, margin, and markup is critical. Return on Investment (ROI) measures the efficiency of an investment by comparing the gain to the cost. Profit margin, on the other hand, tells you what percentage of your total sales revenue is actually profit after all costs are paid.
Markup is often confused with margin, but it represents the percentage added to your cost to determine the selling price. For instance, a 50% markup on a $100 item results in a $150 sale price, but this only represents a 33.3% profit margin. Using our profit margin calculator ensures you price your products correctly and understand your bottom line with precision.
Real-world use cases
Business Owners
Calculate exact profit margins and markups to ensure your pricing strategy covers all overheads and hits profit targets.
Investors
Compare the ROI of different assets and use the compound interest calculator to project long-term wealth growth.
Freelancers
Easily calculate sales commissions and account for GST or VAT when invoicing international clients.
Accounting Students
Verify your financial math homework and visualize how different compounding frequencies affect total interest.