Percentage Calculator
Percent of, percent-of-total, and percent change.
Math and Finance Calculators
Percentages, statistics, interest, loans, VAT, tips, and discounts—transparent calculators that run locally. Browse this curated wowTools collection of local
Overview
Math and Finance Calculators covers the arithmetic people repeatedly get wrong under time pressure: percentage change, summary statistics, compounding, loan amortisation, tax added or removed, and everyday splits. Each tool shows the components of the result so you can sanity-check the number instead of trusting a single output.
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Statistics Calculator
Count, mean, median, mode, and stdev from a list.
Compound Interest Calculator
Future value and interest earned from compounding.
Loan Payment Calculator
Amortized monthly loan payment and total interest.
VAT Calculator
Add or remove VAT and see net/gross amounts.
Tip Calculator
Tip amount, total, and per-person bill split.
Discount Calculator
Final price and savings from a percent-off discount.
Age Calculator
Age in years, months, and days between two dates.
Aspect Ratio Calculator
Simplify a ratio and scale to a target dimension.
Prime Number Checker
Check primality and list primes up to a limit.
BMI Calculator
BMI and weight category in metric or imperial.
GPA Calculator
Weighted 4.0-scale GPA from grades and credits.
Why these tools
Financial mistakes cluster around direction and compounding—removing a percentage by subtracting it, or ignoring how often interest is applied. Grouping these calculators keeps the inputs explicit and makes the intermediate values visible.
Related articles
- When to reach for Percentage CalculatorPercent of, percent-of-total, and percent change. A practical guide to Percentage Calculator: when it fits, how to get a reliable result, and the mistakes worth avoiding.
- Unit conversion without the rounding trapsWhy unit conversions go wrong—ambiguous unit names, offset scales, decimal versus binary prefixes—and how to keep results honest.
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Frequently asked questions
- Is this financial advice?
- No. These calculators perform arithmetic on the numbers you enter. Taxes, fees, and variable rates change real outcomes, so treat results as estimates for your own review.
- How do I remove VAT from a gross price correctly?
- Divide by one plus the rate rather than subtracting the percentage. VAT Calculator handles both directions and shows net, tax, and gross together.
- Which statistic should I report for skewed data?
- Prefer the median when outliers exist, and include a spread measure. Statistics Calculator returns count, mean, median, mode, range, and standard deviation together for that reason.
- Does the compound interest tool account for inflation?
- No. It projects nominal growth from your rate, term, and compounding frequency. Adjust the rate yourself if you want a real-terms estimate.
- Are my figures sent anywhere?
- No. Every calculation runs in your browser, so salary, loan, and health inputs stay on your device.