Calculators
The health calculators — BMI, BMR, Calorie, Body Fat and Water Intake — all use standard, published formulas (Mifflin-St Jeor for BMR and calorie needs, the U.S. Navy tape-measurement method for body fat) rather than anything proprietary, so the math behind each result is the same starting point a dietitian or trainer would use. They're estimates, though: BMI in particular doesn't distinguish muscle from fat and can be misleading for very athletic or very tall or short people, and none of these numbers account for medical conditions, medications or individual metabolic variation. Treat every result here as a reference point for a conversation with a professional, not a diagnosis.
The financial calculators — Tip, Discount and Loan — use straightforward arithmetic (simple amortization for the loan calculator) and are accurate for the numbers you enter, but a real loan quote will also include fees, taxes, insurance requirements and a lender's specific compounding method. Use the loan calculator to compare scenarios quickly, then confirm the real figure with your lender before signing anything.
BMI, BMR and TDEE explained: what the numbers actually meanHow to calculate your exact ageTip calculator guideHow loan calculators work
Frequently asked questions
Which formula does the BMR calculator use?
The Mifflin-St Jeor equation, generally considered more accurate than the older Harris-Benedict formula for most adults. It estimates the calories your body burns at complete rest, before any activity is added.
Why does the loan calculator's total interest look different from my bank's quote?
Bank quotes typically include origination fees, PMI or insurance, taxes and their own compounding schedule, none of which a simple calculator can know about. Use the tool to compare "what if" scenarios — a shorter term, a lower rate — then get the exact figure from the lender.
Is the Body Fat calculator as accurate as a DEXA scan or caliper test?
No — the U.S. Navy tape method used here is a reasonable estimate from a few circumference measurements, but it's less precise than clinical methods like DEXA scans, hydrostatic weighing or skinfold calipers. It's a useful, free way to track trends over time, not a clinical measurement.