TOPSCINET Tools

    Free Online Calculators & Math Tools

    Percentages, conversions, scientific functions and everyday arithmetic, each on its own fast, focused page.

    100% client-side. Nothing is uploaded.No signup required

    All Math tools

    Percentage CalculatorFind X% of a number, percent change, increases and decreases, instantly.Unit ConverterConvert between length, weight, temperature, and more.Scientific CalculatorFull-featured scientific calculator with advanced functions.BMI CalculatorCalculate Body Mass Index with health category indicators.Binary CalculatornewPerform arithmetic and bitwise operations on binary numbers.Length ConverterConvert between meters, feet, inches, miles, and more.Temperature ConverterConvert between Celsius, Fahrenheit, and Kelvin.Days Between DatesFind the exact days between two dates, inclusive, exclusive, and in business days.Zakat CalculatorWork out zakat on cash, gold, silver, business assets, shares, property and livestock.Loan / EMI CalculatornewGet your monthly loan payment, a full amortisation schedule, and prepayment savings.

    About these tools

    A calculator is only useful if it answers the question you actually have. Rather than one overloaded interface, each tool here targets a specific job: working out a percentage change, converting units, running scientific functions, or doing binary and bitwise arithmetic. The Percentage Calculator covers the five cases people genuinely search for: what is P% of X, X is what percent of Y, increase and decrease by a percentage, and percent change between two figures. It shows the formula alongside each answer so you can check the working. The converters handle length, temperature and general units with the conversion factors applied directly, and the Scientific Calculator provides trigonometric, logarithmic and exponential functions for the times a phone calculator is not enough.

    Frequently asked questions

    How do I calculate a percentage increase?

    Subtract the original value from the new value, divide by the original, then multiply by 100. From 80 to 100: (100 − 80) ÷ 80 × 100 = 25%. The Percentage Calculator's '% change' mode does this for you.

    What is the difference between percent change and percentage points?

    They differ. A rate moving from 4% to 6% is a rise of 2 percentage points, but a 50% increase in the rate itself. Use percentage points when comparing two percentages, and percent change when comparing two quantities.

    Are these calculators accurate?

    They use standard IEEE 754 double-precision floating-point arithmetic, the same as spreadsheets and most programming languages. Results are rounded for display but computed at full precision.

    Do I need to install anything?

    No. Every calculator runs in your browser with no download, no signup and no limit on use.