Health calculation collection

Use health and HSA estimates in the right order.

HSA contribution eligibility, adult screening calculations, nutrition arithmetic, activity tools, and date estimates with assumptions and limitations kept visible.

1. Confirm health-account eligibility before funding

HSA contribution room depends on tax-year rules, the plan’s HSA-eligible designation, first-day-of-month eligibility, Medicare, other coverage, employer deposits, and household facts—not medical need or account balance.

2026 HSA Contribution Limit Calculator Estimate one owner’s standard monthly-method limit and remaining room while keeping special-rule exclusions visible. 2026 HSA vs. FSA Decision Guide Compare complete health plans, account eligibility, employer funding, access timing, carryover or forfeiture, spouse coverage, and Medicare.

2. Start health estimates with measurement context

BMI and circumference formulas are inexpensive screening estimates. They do not directly measure health, fitness, fat mass, lean mass, or individual risk.

Adult BMI Calculator Calculate weight relative to height using metric or US measurements. Body Fat Calculator Estimate adult body fat with the US Navy circumference method and explicit measurement limits.

3. Estimate energy before changing it

Begin with resting energy and a broad activity scenario. A formula cannot measure metabolism, and the activity multiplier is often the largest uncertainty.

TDEE and Calorie Deficit Calculator Estimate resting and maintenance energy, then compare a modest fixed daily adjustment without a weight forecast. Macro Calculator Translate an already-chosen calorie target into protein, carbohydrate, and fat grams. BMR, TDEE, Calorie Deficit, BMI, and Body Fat Guide Understand the sequence, formulas, uncertainty, and situations that require individualized care.

4. Track activity and daily timing

Use observed distance and time for activity calculations. Sleep timing options are illustrative and cannot diagnose sleep quality or a sleep disorder.

Running Pace Calculator Calculate average pace and speed from distance and elapsed time. Sleep Calculator Generate illustrative bedtime or wake-time options with explicit timing assumptions.

5. Treat reproductive dates as estimates

Cycle dates and due dates vary. These tools organize dates; they cannot confirm ovulation, conception, pregnancy, gestational age, or fetal health.

Pregnancy Due Date Calculator Estimate cycle-adjusted due date, gestational age, conception date, and a delivery window. Ovulation and Fertile Window Calculator Estimate ovulation, fertile-window, and next-period ranges from entered cycle history.

Health arithmetic is not a diagnosis

Population equations can help organize questions and compare scenarios. They cannot account for symptoms, medical history, medications, laboratory findings, pregnancy, growth, eating-disorder risk, disability, or individual physiology.

These tools provide general educational estimates only. They are not medical, nutrition, fertility, pregnancy, fitness, or treatment advice. Seek qualified care for symptoms, diagnosis, prescribed diets, medication decisions, pregnancy questions, eating-disorder concerns, or unsafe weight-change plans.