Free Health Tools & Calculators
Free, private health calculators and self-checks. Every tool shows how it works and the sources behind it, and nothing you type leaves your browser.
Body & weight
BMI CalculatorBody mass index for adults, in metric or US units, with the lower cut-offs used for South Asian, Chinese and Black adults in the UK.Calorie CalculatorDaily calories to maintain, lose or gain weight (Mifflin–St Jeor equation).Body Fat CalculatorEstimate body-fat percentage from a tape measure (US Navy method).Waist-to-Height Ratio CalculatorThe “keep your waist under half your height” check recommended by NICE.Heart Rate Zone CalculatorMaximum heart rate and five training zones, with or without resting heart rate.Symptom GuideCommon causes of 16 everyday symptoms and the warning signs that need a doctor today.
Periods & pregnancy
Period & Ovulation CalculatorNext periods, likely ovulation day and fertile window for the next six cycles.hCG Doubling Time CalculatorHow fast your hCG level is rising between two blood tests, and what the numbers can and cannot tell you.Pregnancy Due Date CalculatorDue date, how many weeks pregnant you are, trimester and key scan dates.Perimenopause Symptoms ChecklistTick the symptoms you have and print a one-page summary to take to your GP or doctor.When to Take a Pregnancy TestYour likely implantation window, the earliest day a sensitive test might work and the day a test is most reliable.Pregnancy Weeks to Months ConverterWhich month and trimester you are in for any week of pregnancy, with a full 1–42 week chart.Cycle Length Calculator: Is My Period Late?Your average cycle length from past period dates, how regular it is and whether this period is late.Period Blood Colour ChartTap a colour to see what it usually means and when to see a doctor.Menopause Symptom DiaryTrack hot flushes, sleep, mood and bleeding day by day, then print a summary for your GP. Saved only on your device.
Mind & sleep
Phobia Finder: What Is My Fear Called?Find the name of 45 fears, and a 5-question check of whether a fear has become a phobia.Depression & Anxiety Self-Check (PHQ-9, GAD-7)The two questionnaires GPs use to screen for depression and anxiety, scored instantly and privately.Guided Breathing ExerciseBox breathing, 4-7-8 and slow 5.5-second breathing with a visual pacer.Sleep Cycle CalculatorBest times to go to bed or wake up, based on 90-minute sleep cycles.Fear Ladder BuilderBuild the step-by-step exposure plan used in CBT for phobias, sorted from easiest to hardest, ready to print.5-4-3-2-1 Grounding ExerciseA guided, one-sense-at-a-time version of the 5-4-3-2-1 technique for anxiety and panic.
Everyday health
Water Intake CalculatorHow much to drink a day using the EFSA (Europe) and US National Academies reference values.Alcohol Unit CalculatorUK units and US standard drinks for any drink, against the 14-units-a-week guideline.Home Remedy FinderEvidence-rated home care for 12 common minor problems — and when to stop and see a doctor.