Free Online Calculators
Some numbers are worth double-checking: the monthly payment on a mortgage, how much a savings account will grow, the right tip for a group dinner, or the calories you need to hit a fitness goal. These free calculators give instant answers with the working shown, so you can see how the result was reached instead of trusting a black box.
For money, the Loan & Mortgage Calculator produces a full amortization schedule, the Compound Interest Calculator projects growth with regular contributions, and the Tip Calculator splits a bill between up to 50 people. For health, the BMI Calculator uses WHO categories and the Calorie Calculator estimates BMR and TDEE with the Mifflin-St Jeor equation, in metric or imperial units. Everyday math is covered by the Percentage Calculator, an exact Age Calculator, a GPA and grade calculator, and a full Scientific Calculator with trig, logs and calculation history.
All calculations happen instantly in your browser, with nothing to install and no account required. Results are estimates for planning purposes, not financial or medical advice.
All Calculators (11)
Finance CalculatorsCollection
Loan, tip and compound interest calculators.
Open tool →Health CalculatorsCollection
BMI and calorie (TDEE) calculators.
Open tool →Loan & Mortgage Calculator
Monthly payments and amortization schedule.
Open tool →Compound Interest Calculator
Project savings growth with compounding.
Open tool →Tip Calculator
Calculate tips and split the bill.
Open tool →BMI Calculator
Body mass index with WHO categories.
Open tool →Calorie Calculator
TDEE, BMR and macro breakdown.
Open tool →Scientific Calculator
Trig, log, powers and factorials.
Open tool →Percentage Calculator
Percent of, change and difference.
Open tool →Age Calculator
Exact age in years, months and days.
Open tool →GPA Calculator
GPA and final grade calculator.
Open tool →Frequently Asked Questions
Which calculators are available on NJHTools?↓
Loan & mortgage, compound interest, tip & bill splitter, BMI, calorie (TDEE/BMR), percentage, age, GPA & grade, and a scientific calculator. The finance and health calculators are also grouped on their own hub pages.
Are these calculators free?↓
Yes. Every calculator is completely free with no signup, no usage limit and no paywalled features.
How accurate are the finance calculators?↓
They use the standard amortization formula M = P × r(1+r)ⁿ / ((1+r)ⁿ − 1) and standard compound interest math. Real loans may include fees, taxes or insurance, so treat the results as estimates and confirm with your lender.
Which formula does the calorie calculator use?↓
The Mifflin-St Jeor equation for BMR, multiplied by an activity factor to estimate TDEE (maintenance calories). It supports metric and imperial units.
Do the calculators work on mobile?↓
Yes. All calculators are responsive and run in any modern mobile or desktop browser.
Browse other categories
Last updated: