Free calculators that respect your privacy
Calkura is a growing collection of free online calculators covering finance, health, education and everyday needs. Built to do the things a quick search widget can't — model amortization schedules, calculate TDEE, plan your final exam score, or find your exact age. There's no sign-up and no paywall, and because every calculation runs entirely in your browser, the numbers you enter never leave your device.
What you can work out
- Compound interest — how savings grow with an initial deposit plus regular monthly contributions and any compounding frequency.
- Savings goal — exactly how much to set aside each month to hit a target by a chosen date, including interest.
- Mortgage payoff — how extra monthly payments shorten your mortgage and how much interest you save.
- Loan payoff — monthly payment, total interest and a full amortization schedule for any car, personal or student loan.
- Percentages — percent of a number, what percent one number is of another, and percentage change.
- Credit card payoff — enter balance, APR and monthly payment to see the payoff date and total interest.
- Investment returns — project future portfolio value or calculate the CAGR needed to reach a target.
- Rent vs buy — compare total costs, find the break-even year and see which builds more net wealth.
- Debt payoff — compare the snowball and avalanche strategies across multiple debts side by side.
- Salary converter — convert any pay rate to hourly, daily, weekly, bi-weekly, monthly, and annual in seconds.
- Car loan — monthly payment, total interest and full amortization schedule for any auto loan, with extra payment scenarios.
- HELOC — payments during draw and repayment periods, total interest, and available credit for a home equity line.
- BMI — body mass index, weight category and healthy weight range in metric or imperial.
- TDEE — total daily energy expenditure and calorie needs for weight loss, maintenance or gain.
- Age — exact age in years, months and days, plus zodiac sign and next birthday countdown.
- Grade — weighted class average from your assignments with custom weights.
- Final grade — what score you need on the final exam to reach your target.
Learn the “why” behind the numbers
Our plain-English guides explain the ideas behind the financial tools — for example how compound interest works, how much emergency fund you need, choosing between a 15- vs 30-year mortgage, and how much to save for a house down payment.
Frequently asked questions
- Are Calkura's calculators free?
- Yes — every calculator is completely free, needs no sign-up, and runs entirely in your browser.
- Is my data private?
- Yes. The numbers you enter are processed locally in your browser and are never sent to or stored on a server.
- Which calculators are available?
- Compound interest, savings goal, mortgage payoff, loan payoff, percentage, credit card payoff, investment return, rent vs buy, debt payoff (snowball/avalanche), salary converter, car loan, HELOC, BMI, TDEE, age, grade and final grade — with more added over time.