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Free, accurate calculators for finance, health, math, dates, and everyday life — every formula built from a published source and independently reviewed.
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Mortgage CalculatorEstimate your monthly mortgage payment, total interest, and payoff schedule from home price, down payment, rate, and term — with taxes, insurance, and PMI.BMI CalculatorCalculate your Body Mass Index from height and weight, with the WHO category, your healthy-weight range, BMI Prime, and Ponderal Index.Percentage Calculator — what percent one number is of anotherWork out what percent one number is of another: percentage = part ÷ whole × 100. Enter a part and a whole to get the exact percentage, with the steps shown.Scientific Calculator — trig, logs, powers, and rootsA free online scientific calculator with sine, cosine, and tangent (and inverses), natural and base-10 logarithms, powers, roots, factorials, π and e, parentheses, and a degrees/radians switch.Income Tax CalculatorEstimate your 2026 US federal income tax from filing status and income, with a bracket-by-bracket breakdown, effective rate, and marginal rate — from IRS figures.Loan Calculator — compare rates & terms side by sideCompare loan scenarios: monthly payment and total cost for one amount at different rates and terms. See whether a shorter term or a lower rate actually saves more.GPA Calculator — grade point averageCalculate your GPA from letter grades and credit hours. GPA is the credit-weighted average of grade points on the 4.0 scale. For B (3 credits), A- (4), C (2) and C (3) the GPA is about 2.81.Length Converter — meters, feet, inches, miles & moreConvert length and distance between metric and imperial units — meters, centimeters, kilometers, inches, feet, yards and miles. 1 meter is 3.2808 feet.
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Calorie Deficit Calculator — daily target for weight lossFind your daily calorie target to lose weight — maintenance calories minus your chosen deficit. Mifflin-St Jeor BMR and FAO activity levels.Height Calculator — predict a child's adult heightPredict a child's adult height from the parents' heights using the mid-parental (target height) method — for boys and girls, with the expected ±10 cm range.Peptide Reconstitution Calculator — dose, draw volume & syringe unitsWork out the concentration after mixing, how many units to draw on a U-100 insulin syringe for a target dose, and doses per vial. Reconstitution math only — not medical advice.VA Disability Calculator — combined rating (38 CFR 4.25)Combine your VA disability ratings the way the VA does — by the 38 CFR 4.25 efficiency method, not by adding them — and get your rounded combined rating.Grade Calculator — your weighted course gradeWork out your weighted course grade from each assignment or category score and its weight — the weighted average, with the steps shown. Enter scores and weights.BAC Calculator — estimate blood alcohol content (Widmark)Estimate your blood alcohol content (BAC) from body weight, sex, standard drinks and time using the Widmark formula. An estimate only — never use it to decide whether to drive.