Basic arithmetic, scientific functions, percentage problems, unit conversions across 8 categories, and GST calculations for all Indian slabs - all free, all instant, all in your browser.
Five calculators covering the most common math tasks - arithmetic, scientific functions, percentage problems, unit conversions, and Indian GST.
Mobile phones have calculators built in. Spreadsheets can do anything. So why does a dedicated online calculator still get millions of searches every month?
Because the built-in phone calculator doesn't have a calculation history. Spreadsheets take 30 seconds to open. And when you're doing something specific - like working out GST on a ₹47,500 invoice, or converting 5 feet 11 inches to centimetres - you want a calculator that knows what you're doing and shows its work.
Our percentage calculator handles four different types of percentage problems in one place. Most people can do "what is 15% of 300" in their head. But "300 is what percentage of 850?" or "what was the original price if the current price is ₹560 after a 30% increase?" - that's where a purpose-built calculator saves time.
The GST calculator is particularly India-specific. It handles all five slabs, splits automatically into CGST+SGST for intra-state or IGST for inter-state, and includes a multi-item invoice builder where you can add multiple line items at different GST rates and get a total invoice value.
Students use the scientific calculator for board exam practice (Class 10, 11, 12) and competitive exam preparation - JEE, NEET, UPSC. The percentage calculator handles the classic "marks percentage" problem that comes up every result season.
Professionals use the unit converter constantly: civil engineers converting mm to inches on imported equipment specs, doctors converting kg to lbs for international drug dosages, IT professionals converting GB to TB for storage planning.
The unit converter covers 8 measurement categories: length (mm to km, inches to feet, miles to km), weight (grams to kg, ounces to pounds), temperature (°C to °F and Kelvin), area (sq ft to sq m, acres to hectares), volume (mL to L, cups to litres), speed (km/h to m/s, mph), time (seconds to hours, days to years), and data storage (KB to GB, bits to bytes). It converts as you type - no button press needed.
One detail worth noting: temperature conversion from Celsius to Fahrenheit is not a simple multiplication - it is (°C × 9/5) + 32. The unit converter handles this correctly, whereas simple search results sometimes give the wrong formula.
Percentage change = ((New value - Old value) ÷ Old value) × 100. Positive result means increase, negative means decrease. Example: price went from ₹500 to ₹600 - change = ((600-500) ÷ 500) × 100 = 20% increase. To find the original value from a discounted price: Original = Discounted price ÷ (1 - discount%/100). For a ₹400 item after 20% discount: original was 400 ÷ 0.80 = ₹500.
Eight categories: length (from mm to km, also feet/inches/miles), weight (mg to tonnes, oz to lbs), temperature (Celsius/Fahrenheit/Kelvin), area (sq cm to sq km, sq ft, acres, hectares), volume (mL to L, cups, gallons), speed (km/h, m/s, mph, knots), time (seconds to years), and data storage (bits to TB). It converts as you type, so you see the result immediately without pressing a button.
Yes - the scientific calculator is fully responsive and works on mobile browsers. All standard functions are accessible: trig (sin/cos/tan), inverse trig, natural log (ln), log base 10, e^x, x^y, square root, cube root, factorial, and constants like π and e. You can switch between degree and radian mode using the DEG/RAD toggle.
All math and science calculators are free, work in your browser, and save your calculation history. No account required.