Free, instant online tools
Calculators, converters, comparisons, and reference tables that load fast and work instantly. No signup. No nonsense.
Calculators
Instant answers to how-much and how-many questions.- Kcat CalculatorEasily calculate the catalytic constant (kcat) of an enzyme using substrate concentration and reaction velocity formulas.
- Net Income CalculatorEasily calculate net income by subtracting expenses and taxes from your total revenue. Free online tool for business and personal use.
- GPA CalculatorEasily calculate your GPA (Grade Point Average) for a single semester or cumulative. Supports standard 4.0 scale grading.
- Salary Calculator — Gross to Net & Pay PeriodsEasily convert annual salary to monthly, weekly, or hourly rates. Calculate gross pay and estimate net income across different pay frequencies.
- Investment Portfolio CalculatorAdd each holding's amount and expected return to see your portfolio's total value and blended annual return.
- Mortgage Payment CalculatorCalculate your monthly mortgage payment and total interest from the loan amount, rate, and term.
- LLM VRAM CalculatorEstimate the GPU VRAM needed to run a large language model at a given size, quantization, and context length.
- Compound Interest CalculatorSee how your savings grow with compound interest and regular contributions. Free, instant.
- Tip CalculatorWork out the tip and split any restaurant bill between people instantly. Free, no signup.
Converters
Convert between units in real time.- Data Storage ConverterConvert digital storage units, including decimal (KB, MB, GB) and binary (KiB, MiB, GiB) sizes.
- Temperature ConverterConvert temperatures between Celsius, Fahrenheit, and Kelvin instantly.
- Length ConverterConvert between metric and imperial length units instantly: mm, cm, m, km, inches, feet, yards, and miles.
Date & Time
Ages, deadlines, countdowns, and date math.- Days Until April 20Calculate exactly how many days, weeks, or months are left until April 20. Instant countdown tool for planning events and deadlines.
- Add or Subtract Days CalculatorAdd or subtract days, months, and years from any date to find a deadline or future date, and see which weekday it falls on.
- Date Difference CalculatorCount the days, weeks, and business days between two dates, plus the difference in full years.
- Age CalculatorFind your exact age in years, months, and days from your date of birth, plus total days lived and the day you were born.
Comparisons
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