Utility command center
Numerical operations toolkit
Percentage Calculator
Ratios, changes, and proportional values.
Interest Calculator
Compound growth and interest earnings.
Tax Return Calculator
Estimate liability, refund, or balance due.
Haul Yield
Load efficiency, loss, and gross revenue.
Inflation Calculator
Purchasing power across price index periods.
Video Minute Yield
Creator payout per video minute by platform.
Profit Margin Calculator
Revenue, costs, profit, and markup.
Loan & Mortgage Calculator
Monthly payment, total interest, and amortization.
Hourly to Salary Converter
Hourly wage to annual, monthly, and weekly pay.
Discount & Sales Tax Calculator
Final price after a discount and sales tax.
2026 tax guide
Freelancer Tax Calculator & GuideFrequently asked questions
About NumberChan
Is NumberChan free to use?
Yes. Every calculator is free, with no accounts, sign-ups, or subscriptions. Advertising helps support the site.
Are my calculations sent anywhere?
No. The math runs in your browser. Recent Calculations and Saved Results are stored only on your device, and you can delete them at any time.
Can I rely on the results for financial or tax decisions?
Results are educational estimates based on standard formulas. For important decisions, check them with a qualified professional.
Can I share or print a calculation?
Yes. Calculator pages include a share link that reopens the same inputs, plus a print option you can also save as a PDF.
Numbers in general
What is the difference between percent and percentage points?
Going from 10% to 15% is a rise of 5 percentage points, but a 50% increase in relative terms, because 5 is half of 10.
Why does a 50% drop need a 100% gain to recover?
Percentages apply to the current value. $100 falling 50% becomes $50, and $50 must double (rise 100%) to get back to $100.
What is the difference between margin and markup?
Margin is profit divided by the selling price; markup is profit divided by the cost. A $100 item costing $75 has a 25% margin but a 33.33% markup.
What makes compound interest different from simple interest?
Simple interest is earned only on the original amount. Compound interest is also earned on interest already added, so growth speeds up over time.
Why do rounded percentages sometimes not add up to 100%?
Each figure is rounded separately, so small leftovers can make the total show as 99.9% or 100.1%. That is normal rounding, not an error.