Free Online Calculators
Finance, math, health, construction, and everyday tools in one searchable catalog.
Your calculators
Calorie Calculator — Daily Calorie Intake & Macros
Calculate BMR, TDEE, and daily calories for weight loss, maintenance, or muscle gain in metric or imperial units, with a visual macro breakdown.
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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.
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Retirement Calculator — Savings & Monthly Income
Estimate savings at retirement from your age, current balance, and monthly contribution. Then refine income, spending, returns, and inflation.
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Concrete Calculator — Cubic Yards, Bags & Cost
Calculate cubic yards or cubic meters for a slab, footing, column, or stairs. Add waste, then estimate ready-mix loads, bags, and cost.
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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.
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Salary Calculator — Hourly to Annual Pay
Convert hourly, daily, weekly, monthly, or annual gross pay instantly. Optionally adjust schedule, unpaid time, overtime, bonus, and raise.
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Sleep Calculator — Bedtime, Wake Time & Duration
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.
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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.
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Random Number Generator — One Number or a Unique Sample
Generate one number from a clearly labelled inclusive range, or create, sort, copy and download a larger random sample.
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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.
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Age Calculator — Exact Age, Days & Next Birthday
Calculate exact calendar age in years, months and days, total elapsed days, hours and minutes, age on any date, and the next birthday.
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Free Date Calculator — Days Between Dates & Age Calculator
Calculate days between dates, add or subtract days, or find an exact age with weekend controls, clear steps, and instant visual results.
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