Wellness tools
Four calculators. Your inputs, right here.
Every result includes the formula's assumptions and where it falls short. These are educational estimates, not medical assessments.
Heart Rate Reserve
Karvonen method — estimates training zones from your heart rate reserve rather than max heart rate alone.
Result
Assumptions & limitations
- Max HR is estimated as 220 minus age, a population average with wide individual variation.
- Not adjusted for medication, cardiovascular conditions, or fitness level.
- Consult a clinician before starting a new exercise intensity.
Hydration Target
A general baseline fluid estimate adjusted for activity and climate.
Result
Assumptions & limitations
- Baseline of roughly 33ml per kg of body weight, a common general guideline.
- Doesn't account for medical fluid restrictions or kidney, heart, or thyroid conditions.
- Fluid from food and other beverages also contributes to daily intake.
BMI / BMR
Body mass index and estimated resting energy expenditure (Mifflin-St Jeor).
Result
Assumptions & limitations
- BMI does not distinguish muscle from fat mass or account for frame size.
- BMR estimates resting needs only, before activity is added.
- Not valid during pregnancy or for children.
Sleep Architecture
Back-plans a bedtime using full 90-minute sleep cycles ending near your wake time.
Result
Assumptions & limitations
- Assumes an average 90-minute cycle length; actual cycles vary by person and night.
- Does not account for sleep disorders, shift work, or medication effects.
- A scheduling guide, not a diagnostic sleep assessment.
Not sure what a result means for you?
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