Free Online Calculators
Finance, math, health, construction, and everyday tools in one searchable catalog.
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Adult BMI Calculator — BMI, Healthy Weight & Chart
Body Fat Calculator — Navy Method & Lean Mass
Calorie Calculator
Ovulation Calculator — Fertile Window & Cycle Calendar
Pregnancy Due Date Calculator — Weeks, IVF & Timeline
Running Pace Calculator — Time, Distance & Splits
Sleep Calculator
Water intake calculator — daily hydration range
Calculator descriptions
Adult BMI Calculator — BMI, Healthy Weight & Chart
Calculate adult BMI in metric or US units. See the CDC category, healthy weight range for your height, distance to the range, formula, and a visual BMI chart.
Body Fat Calculator — Navy Method & Lean Mass
Enter height, neck and waist (plus hip for the female equation) to see the estimate immediately; optionally add weight for fat mass, lean mass and a target scenario.
Calorie Calculator
Calculate BMR, TDEE, and daily calories for weight loss, maintenance, or muscle gain in metric or imperial units, with a visual macro breakdown.
Ovulation Calculator — Fertile Window & Cycle Calendar
Estimate ovulation, fertile-window and next-period dates from an average cycle or a variable cycle-length range, with a visual calendar and three-cycle forecast.
Pregnancy Due Date Calculator — Weeks, IVF & Timeline
Estimate your due date and gestational age from last period, conception, IVF transfer, ultrasound age, or a known clinical due date, with a week-by-week visual timeline.
Running Pace Calculator — Time, Distance & Splits
Calculate running pace, finish time, or distance with only the two values you know, then optionally build exact even or negative splits.
Sleep Calculator
Plan bedtime from a required wake time, find a wake time from bedtime, or measure an overnight sleep window. Compare the result with CDC age guidance and optionally explore variable cycle scenarios.
Water intake calculator — daily hydration range
Estimate a practical daily drinking range from weight, exercise and heat, with glasses, hourly pace and transparent adjustments.
