Calculators & Converters

Quick online calculators and converters: units, percentages, age, BMI and random numbers — accurate, fast and free to use forever.

Convert length, weight, temperature, data and more.

Calculate percentages, ratios and percentage change instantly.

Calculate exact age in years, months and days from any birth date.

Calculate your Body Mass Index with category and healthy weight range.

Generate random numbers within any range, with unique & sort options.

Calculate monthly payments and see the full amortization schedule.

Convert between 30+ world currencies with live rates.

Calculators & Converters — FAQ

Yes — every tool on LahbabiGuide is free to use with no sign-up, no limits and no hidden costs. They always will be.

No. All tools run entirely in your browser using JavaScript — nothing you type, paste or upload is ever sent to a server.

No installation needed. Every tool works in any modern browser on desktop, tablet or phone.