SelHealth Calculators

Daily Water Intake

Estimate daily water needs with SelHealth and understand how to use hydration guidance in a practical everyday way.

How to use this tool
  1. Enter the requested body data.
  2. Review the estimated hydration target.
  3. Adjust upward when heat, exercise, or sweating is higher.
❤️ General Health
SelHealth dark calculator system

Water Intake Calculator

Simple daily estimate based on body weight and activity.

Daily target Lifestyle
Educational Tool Medically reviewed • Last reviewed: 2026-03 • Source: EFSA / IOM • Evidence level: Reference-based educational estimate
Hydration advice here is an educational daily estimate and should be individualized in kidney disease, pregnancy, heart failure, heat exposure, or heavy exercise.

Blood Pressure

Classify your blood pressure reading using systolic and diastolic values.

Self-check Symptoms matter
Screening Tool Medically reviewed • Last reviewed: 2026-03 • Source: AHA / ACC • Evidence level: Guideline-framed screening support
Educational blood pressure interpretation based on clinic thresholds. Single readings do not establish a diagnosis.
Safety notes:
  • Seek urgent care for very high readings with concerning symptoms.

Heart Rate

Estimate your resting heart rate status and basic target zone.

Self-check Resting value
Educational Tool Medically reviewed • Last reviewed: 2026-03 • Source: AHA • Evidence level: Reference-based educational estimate
Resting heart rate interpretation is educational. Medication use, fever, dehydration, thyroid disease, and athletic conditioning can change the reading.

Heart Age

Estimate your heart age using age, blood pressure, resting heart rate, and smoking status.

Educational Lifestyle
Wellness Estimate Medically reviewed • Last reviewed: 2026-03 • Source: NHS-style educational estimate • Evidence level: Wellness support / non-diagnostic guidance
This calculator provides an educational heart-age style estimate and is not a validated cardiovascular risk engine.

Biological Age

A simple educational estimate based on age, resting heart rate, waist, and smoking.

Educational Lifestyle
Wellness Estimate Medically reviewed • Last reviewed: 2026-03 • Source: Educational composite estimate • Evidence level: Wellness support / non-diagnostic guidance
Biological age here is an educational wellness estimate derived from a simplified lifestyle composite and is not a validated biomarker panel.

Diabetes Risk

A simple educational screener based on age, waist, fasting glucose, and activity.

Screening only Not diagnostic
Screening Tool Medically reviewed • Last reviewed: 2026-03 • Source: ADA • Evidence level: Guideline-framed screening support
Fasting plasma glucose ranges are educational and require confirmatory clinical interpretation when abnormal.
Safety notes:
  • This tool does not confirm diabetes and does not replace confirmatory laboratory testing.

Cardiometabolic Risk Snapshot

An educational cardiometabolic risk snapshot using a few common inputs. This is not a validated event-risk calculator.

Educational Not event-risk
Wellness Estimate Medically reviewed • Last reviewed: 2026-03 • Source: AHA PREVENT / cardiovascular prevention concepts • Evidence level: Wellness support / non-diagnostic guidance
This score is a simplified educational review and does not replace validated cardiovascular risk calculators such as PREVENT or ASCVD tools.
Safety notes:
  • This is not a validated ASCVD or PREVENT event-risk calculator.

Cholesterol Review

A simplified educational review of common lipid patterns. It does not replace clinician interpretation within overall cardiovascular risk.

Educational Lipid pattern
Screening Tool Medically reviewed • Last reviewed: 2026-03 • Source: AHA • Evidence level: Guideline-framed screening support
Educational interpretation of common cholesterol ranges; LDL goals and treatment decisions depend on overall cardiovascular risk, not a single number alone.

Metabolic Age Estimate

A simplified motivational estimate based on age, body size, and activity—not a validated clinical metabolic measure.

Educational Lifestyle
Wellness Estimate Medically reviewed • Last reviewed: 2026-03 • Source: Educational wellness estimate • Evidence level: Wellness support / non-diagnostic guidance
Metabolic age is a simplified educational estimate influenced by BMI and activity inputs, not a validated physiologic or laboratory age measure.

Life Expectancy

Estimate a simplified population-style life expectancy using age, sex, smoking, and activity.

Educational Population estimate
Wellness Estimate Medically reviewed • Last reviewed: 2026-03 • Source: CDC population life expectancy context • Evidence level: Wellness support / non-diagnostic guidance
Life expectancy here is a simplified educational estimate anchored to population data and cannot predict an individual lifespan.
What this tool helps you do

This hydration calculator gives you a practical estimate of daily water needs based on body size and routine. It is most helpful as a daily guidance tool, especially when paired with climate, activity, and symptom awareness.

How to read your result

Daily target

Treat the result as a flexible target rather than a rigid rule, especially if your day varies a lot.

Frequently asked questions
Is more always better?

No. Hydration should be balanced with thirst, weather, exercise, and individual medical context.

Related tools

Use these related tools when you want to connect hydration with broader daily recovery, cardio signals, and routine needs.

Water Intake Calculator Open calculator → Heart Rate Open calculator → Cardiometabolic Risk Snapshot Open calculator →