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LongevityMate Tools

Free health calculators that explain the answer

Get a clear result in under a minute, then understand what it means, what can affect it and what to do next. Free. No sign-up.

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61 reviewed tools
FreeFitness and heart health

Strength training volume load calculator

Calculate strength-training volume load from sets, repetitions and external load. Exact kg or lb arithmetic, total reps and clear limitations.

Open toolCaffeine intake calculator combining 95 mg twice and 63 mg once into a 253 mg labelled totalFreeSleep and recovery

Caffeine intake calculator

Add the caffeine stated on up to six product labels. Exact local arithmetic in milligrams, with no safe-limit, dose or timing advice.

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Sleep duration calculator

Calculate time in bed from bedtime and wake time. Optionally subtract awake minutes for a clearly labelled sleep estimate, with no cycle claims.

Open toolConceptual bedroom illustration with a shorter highlighted asleep interval inside a longer in-bed interval; no measured values or diagnosis are shown.FreeSleep and recovery

Sleep efficiency calculator

Calculate a descriptive sleep-efficiency percentage from matching asleep and in-bed hours. See the exact formula, impossible-input guard and measurement limits.

Open toolAlcohol-free streak calculator showing two calendar dates and an exact completed-day countFreePreventive health

Alcohol-free streak calculator

Count completed alcohol-free calendar days between two dates, plus the inclusive streak day and exact weeks-and-days breakdown.

Open toolFreePreventive health

Celsius to Fahrenheit converter

Convert one recorded temperature between degrees Celsius and degrees Fahrenheit using the exact scale relationship, without interpreting the reading.

Open toolA phone and laptop sit inside three neutral time arcs representing 7-day, 30-day and 365-day screen-time projections.FreePreventive health

Daily screen time calculator

Turn an average daily screen-time duration into neutral 7-day, 30-day and 365-day totals, without scores, targets or judgement.

Open toolFreePreventive health

Smoking cost and savings calculator

Calculate cigarette spending over 1, 7, 30 and 365 days from your own pack price and pack size. Private, currency-neutral arithmetic.

Open toolFreePreventive health

Smoking pack-years calculator

Calculate cigarette pack-years from average cigarettes per day and years smoked. See the formula, limits and what the result cannot tell you.

Open toolEPA and DHA label calculator illustration showing separate label amounts multiplied by servings and added into one combined totalFreeSupplements

EPA and DHA label calculator

Multiply EPA and DHA amounts from a label by the servings entered, then see separate and combined totals without dose or target advice.

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Supplement bottle calculator

Estimate how many days a supplement container will last from the amount in it and the amount used per day. Inputs and results stay in your browser.

Open toolSupplement printed-date calculator illustration comparing two complete calendar dates to produce a neutral calendar-day differenceFreeSupplements

Supplement expiry date calculator

Count exact calendar days until or past a full date printed on a supplement label, without judging safety, potency or suitability.

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Vitamin D IU to mcg converter

Convert vitamin D2 or D3 label amounts between international units (IU) and micrograms (mcg) using the exact 1 mcg = 40 IU relationship.

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Clear evidence. Private inputs.

Each calculator must publish its formula, assumptions, eligible population, exclusions, sources, version and review date.

Calculator inputs and results are not placed in URLs or analytics. A tool can be disabled or rolled back without replacing its stable URL.