Exact age in years, months, days — plus next birthday.
Days between dates, or add/subtract days.
What is X% of Y, percent of total, percent change.
Length, weight, temperature, area, volume, speed, data.
Body mass index with category, metric or imperial.
Spin a wheel to pick a random winner.
Daily calories (BMR + activity) to maintain or lose.
Pregnancy due date from last period, with milestones.
Running pace, time or distance — solve any one.
Tip and per-person split for any bill.
Sale price after % off — and % off between prices.
Monthly payment, total interest, amortization.
Growth of savings with monthly contributions.
Weighted GPA from courses, credits and grades.
Roll any dice — d6, d20, as many as you like.
Random numbers in any range, with no repeats option.
Count down to any date, or set a quick timer.
25-minute focus sessions with breaks.
Compare times across world cities.
Current ISO week, and week number of any date.
Flip a coin — heads or tails, instantly fair.
Total daily energy expenditure from your stats.
Basal metabolic rate by Mifflin-St Jeor and Harris-Benedict.
Body fat percentage by the US Navy tape method.
Daily protein, carbs and fat for your goal.
Estimate your 1RM from any set.
Healthy weight range for your height.
Hours between two times, minus breaks.
Weekly timesheet with overtime and pay.
Best bedtime or wake time by sleep cycles.
Weighted course grade + score needed on the final.
Add or back out sales tax, with US state rates.
Area of rooms and odd shapes, with cost.
Trip fuel cost from distance, consumption and price.
Standard deviation, variance and the working behind them.
All three averages plus quartiles and spread.
Z-score, percentile and the bell curve drawn.
Intervals for a mean or a proportion, using t or z correctly.
p-value from a z statistic, with the tails drawn.
How many responses a survey actually needs.
Combined probability of two events, plus repeated trials.
Greatest common factor, two ways, with the working.
Least common multiple, with both methods shown.
Break any number into primes, with a factor tree and all divisors.
Add, subtract, multiply and divide fractions with steps.
Simplify ratios, solve proportions, split a total.
Percent error, absolute error and percent difference.
Solve ax² + bx + c = 0 with steps and the parabola drawn.
Solve for any side of a right triangle, with the triangle drawn.
Solve a triangle from its three sides, drawn to scale.
Radius, diameter, circumference and area from any one of them.
Slope, intercept and line equation from two points.
Area of six common shapes, with the shape drawn.
Full scientific calculator with a running tape.
Solve for x, with the curve drawn.
Differentiate step by step, with the tangent drawn.
Multiply, invert, reduce and solve, with every result checked.
Interactive periodic table with search and details.
Molar mass, percent composition and mole conversions.