Calculate simple and compound interest for loans or investments.
Simple Interest is calculated using the formula: Interest = Principal × Rate × Time
Compound Interest is calculated using the formula: A = P(1 + r/n)^(nt), where A is the final amount, P is principal, r is annual interest rate, n is compound frequency, and t is time in years.
Compound interest is more powerful than simple interest because you earn interest on both your original principal and previously earned interest.
Explore how much interest accrues when it is calculated only on the original principal. Using I = P × r × t, where P is principal, r is the annual rate, and t is time in years, simple interest grows linearly with time and does not compound. This structure is common in short‑term notes, certain promotional financing, or for quick estimates in educational settings. Because prior interest never earns additional interest, the amount owed or earned increases at a steady pace. This calculator helps you compare the total interest under simple assumptions versus compounding alternatives by holding P, r, and t constant. It is useful for understanding the baseline cost of capital and for sanity‑checking offers that advertise low rates but embed fees elsewhere. If fees are included, distinguish between interest and non‑interest costs; fees raise the effective cost even if the nominal rate seems low.
Model growth when interest is periodically added to principal so future interest is calculated on an ever‑increasing base. The formula A = P(1 + r/n)^(n×t) computes ending amount A given principal P, annual rate r, compounding frequency n (e.g., monthly 12), and time t in years. Compounding accelerates growth relative to simple interest; the effect scales with both rate and time. This tool lets you vary n to see how monthly versus annual compounding changes results and to test scenarios like daily compounding for savings accounts. For loans, compounding determines how interest accrues between payments; for investments, it shows how reinvested earnings can meaningfully increase long‑term value. To approximate real‑world outcomes, remember that taxes and fees reduce the effective rate, and volatility means realized paths differ from smooth curves. Use conservative assumptions for short horizons or essential goals.
If you want to see how interest accumulates each month, a monthly interest calculator gives a clear snapshot. Enter your principal, the monthly rate, and the period to get month-by-month figures, ideal for budgeting and short-term planning. This approach is excellent for comparing different savings or short-term investment options.
Banks often provide a bank interest calculator to show projected balances with different account types. An interest rate calculator helps compare offers side-by-side so you can pick the best account or fixed deposit. Use both tools to evaluate promotional rates and compounding rules before deciding where to park your money.
Compare a loan calculator, loan repayment calculator, and an online loan calculator when evaluating borrowing options.
Check both the Loan interest calculator and its outputs; they may label fields differently but aim to show monthly payments, total interest, and payoff dates.
Use free online calculators often bundle these loan tools so you can test scenarios without any cost.
Want figures in local currency? Try the Interest calculator in rupees to see exact amounts in INR. If you prefer to understand the math, the Interest Calculator formula typically uses principal × rate × time for simple interest or the compound formula for repeated compounding. If you’re wondering how much interest you will earn on a particular deposit, plug your values in and review the timeline for precise results. Beyond quick estimates, using multiple calculators side-by-side reveals hidden trade-offs: lower monthly payments can mean higher total interest, while slightly higher rates with shorter terms reduce lifetime costs. Track scenarios in a simple table, note the principal and total interest, and review amortization schedules when comparing lenders. If you manage multiple accounts, set reminders to revisit rates annually and rerun projections; small percentage differences add up over years. Use secure sites and double-check inputs to ensure accurate projections.