Calculator Tools
13+ free online calculators for math, finance, health, and everyday calculations.
About the Online Calculators
NKable's online calculators cover the everyday sums people search for: body mass index, loan repayments, percentage change, exact age, restaurant tips, date differences, unit conversion and scientific functions. Every calculation runs in your browser, so nothing you type is sent anywhere or stored.
These online calculators handle the questions that come up away from a spreadsheet — what a loan actually costs per month, what percentage a price rose by, how many days until a deadline, how to split a bill fairly, or what 6 feet 2 inches is in centimetres.
Each one shows its working rather than only a final number. The loan calculator gives a full amortisation schedule, the BMI calculator names the category the result falls in, and the percentage calculator covers increase, decrease and reverse percentage in one place.
Everything runs in your browser. Financial figures, health measurements and dates are never uploaded, stored or logged — the arithmetic happens on your own machine.
How to use the Online Calculators
- Pick a calculator. Choose the calculation you need from the list below.
- Enter your figures. Type your numbers. Results update as you type, with no submit step.
- Read the breakdown. Look at the working, schedule or category shown alongside the answer.
- Adjust and compare. Change an input to compare scenarios instantly.
Online Calculators features
- Thirteen calculators, from BMI and loans to bitwise operations
- Results update as you type
- No registration or signup
- Works on a phone as well as a desktop
- Every calculation runs in your browser
Frequently asked questions
Are these calculators free?
Yes, all of them, with no account and no usage limit. There is nothing to install either — each one is a web page.
Is anything I type sent to a server?
No. Every calculator here runs entirely in your browser, which matters for the ones handling personal figures — loan amounts, salaries, dates of birth and BMI inputs are never transmitted, logged or stored.
Which calculators are available?
BMI, age, loan and EMI, percentage, unit conversion, scientific, tip, random numbers, date difference, aspect ratio, bitwise, time arithmetic and prime and Fibonacci tools.
Can I rely on the results for financial decisions?
Treat them as accurate arithmetic on the figures you supply, not as advice. A loan schedule here shows what those inputs imply; the lender's own numbers may include fees or rounding rules this does not know about.
Do they work on a phone?
Yes, the layouts adapt to small screens. The tip and unit converters in particular are built with phone use in mind, since that is usually where you need them.