Last updated: October 6, 2026
Free Everyday Calculators
BMI, calories & macros, GPA & finals, tips, ages, percents & pay — instant answers, zero signup, fully private.
BMI Calculator
Body mass index with WHO categories, healthy weight range, and a visual scale.
Open calculatorCalorie & Macro Calculator
TDEE from Mifflin-St Jeor plus daily protein, carb, and fat targets for your goal.
Open calculatorGPA Calculator
Weighted semester GPA, cumulative GPA, and a final-exam grade solver.
Open calculatorTip & Bill Splitter
Tip percentages, sales tax, and exact per-person shares in one tap.
Open calculatorAge Calculator
Exact age, days between dates, and live event countdowns.
Open calculatorPercentage Calculator
Percents, changes, discounts, and original-price finder.
Open calculatorHourly–Salary Converter
True annual pay with overtime and unpaid time off.
Open calculatorSmall Questions, Exact Answers
The questions these calculators answer come up weekly: Am I in a healthy range? BMI in one number. How much should I eat to lose a pound a week? TDEE minus 500, with macros. What do I need on the final to keep my A? The solver knows. What is 20% on $86 split three ways? Answered before the card arrives.
Every tool uses the standard published formula — WHO cutoffs, Mifflin-St Jeor, 4.0 weighting — and shows its work so you can sanity-check the result. Nothing is uploaded, nothing needs an account, and each page explains the formula in plain language. For money questions, the finance calculators cover paychecks, mortgages, loans, and investing with the same private math.
Frequently Asked Questions
Are these calculators free?
Yes — all four are 100% free with no signup and no limits. They run entirely in your browser, so your numbers never leave your device.
How accurate are the results?
Math is exact for the published formulas: WHO BMI cutoffs, Mifflin-St Jeor BMR with standard activity factors, 4.0 GPA weighting, and percentage-based tips. Bodies, metabolisms, and school grading scales vary — treat results as estimates, and confirm health decisions with a professional.
Is my health and grade data private?
Completely. Every calculation happens locally in your browser. No weight, grades, or bill amounts are uploaded, stored, or tracked.
Which formula does the calorie calculator use?
Mifflin-St Jeor for BMR (the clinical standard), multiplied by activity factors 1.2–1.9 for TDEE, with −500 kcal for fat loss and +250 kcal for lean muscle gain, plus a 30/40/30 protein/carb/fat macro split.
Does the GPA calculator handle weighted grades?
Yes — Regular, Honors (+0.5), and AP/IB (+1.0) levels per course, capped at 5.0, plus cumulative GPA blending and a final-exam solver that tells you exactly what score you need.
Do you have finance calculators too?
Yes — paycheck take-home for all 50 states, mortgage payments, loan EMIs, and investment growth live in the finance section.