6 free everyday calculators

    Everyday calculators
    for the small numbers in life.

    Your exact age, the days between two dates, BMI, daily calories, a quick percentage, a tip split four ways — the small calculations you reach for all the time, each on its own clean page. No signup, no paywall.

    Date & Time

    Health & Fitness

    Everyday Math

    The everyday maths you actually do

    Not every calculation is about money. Most of the numbers we work out in a normal week are small and personal — how old someone is to the day, how many days until a deadline, whether a weight is in a healthy range, how to split a restaurant bill, or simply what twenty percent of something comes to. These tools cover those moments. Each one does a single job well, shows the answer the instant you type, and explains the method underneath so you can trust the result and learn the shortcut for next time.

    Accurate where accuracy matters

    The date and age calculators count real calendar months and leap days rather than dividing by an average year, so they match how age and durations are officially recorded. The BMI and calorie tools use the standard WHO categories and the Mifflin-St Jeor equation that dietitians rely on. The percentage and tip calculators apply the textbook formulas and handle the awkward cases — like why a 50% rise and a 50% fall do not cancel out — that trip people up. Where a result is an estimate rather than a fact, the page says so.

    A quick note on the health tools

    The BMI and calorie calculators are general screening and planning tools, not medical advice. They cannot account for muscle mass, body composition, pregnancy, age extremes or medical conditions, and they are not designed for children. Use them as a starting point and a way to track changes over time, and speak to a doctor or registered dietitian for guidance tailored to you.