Formulas
How to Use
Choose the tab based on what you want to calculate — SI, Principal, Rate, or Time.
Fill in the three known values. Rate is per annum; Time is in years.
Click Calculate to see the result with a full breakdown including Total Amount.
Frequently Asked Questions
SI = (P × R × T) ÷ 100. Total Amount = P + SI. Here P = Principal, R = Rate of interest per annum (%), T = Time in years.
P = (SI × 100) ÷ (R × T) = (2400 × 100) ÷ (8 × 3) = 240000 ÷ 24 = ₹10,000.
In Simple Interest, interest is calculated only on the original principal. In Compound Interest, interest is added to the principal each period, so future interest is earned on interest too. For the same P, R, T: CI > SI (except for T=1 year, where they are equal for annual compounding).
SI is a core topic in SSC CGL, SSC CHSL, IBPS PO, SBI PO, SBI Clerk, RRB NTPC, LIC AAO, and CAT. Typically 1–3 questions appear per exam.