Finance

• Compound interest Future value of a sum that earns interest on its interest.
• Loan EMI Monthly installment, total interest, and amortization for a fixed-rate loan.
• Annual annuity Yearly savings → future value, or corpus → yearly payout.
• Monthly annuity Monthly savings → future value, or corpus → monthly payout.
• Currency converter Live forex rates between 30+ currencies, from European Central Bank reference rates.

Health

• BMI calculator Body Mass Index from weight and height, in metric or imperial units.
• Age calculator Exact age in years, months, and days — plus total days, weeks, and months.

Maths

• Prime factorization Unique prime factors of any integer — plus all divisors, divisor count, and divisor sum.
• Roman numeral converter Convert a number to Roman numerals or decode a Roman numeral back to a number (1–3999).

Science

• pH / acid-base calculator pH, pOH, [H⁺] and [OH⁻], plus the pH of strong and weak acids and bases from concentration and Ka or Kb.