The State Bank of India (SBI) offers Fixed Deposits (FDs) as a secure investment option for individuals looking to earn a fixed return on their savings. The interest earned on an FD depends on several factors: the principal amount deposited, the annual interest rate offered by SBI, the tenure (duration) of the deposit, and how frequently the interest is compounded.
This calculator helps you estimate the maturity amount and the interest earned on your SBI FD. We use the compound interest formula, adjusted for different compounding frequencies, to provide an accurate projection.
The Compound Interest Formula
The general formula for compound interest is:
A = P (1 + r/n)^(nt)
Where:
A = The future value of the investment/loan, including interest (Maturity Amount)
P = The principal investment amount (the initial deposit)
r = The annual interest rate (as a decimal)
n = The number of times that interest is compounded per year
t = The time the money is invested or borrowed for, in years
How the Calculator Works
Our calculator simplifies this by taking your input for:
Deposit Amount (P): The initial sum you invest.
Annual Interest Rate (%): The rate SBI offers for the FD. This is converted to a decimal (r) by dividing by 100.
Tenure (Months): The duration of your FD. This is converted to years (t) by dividing by 12.
Interest Compounded: This determines the value of 'n' based on the frequency selected:
Annually: n = 1
Semi-Annually: n = 2
Quarterly: n = 4
Monthly: n = 12
The calculator then computes the Maturity Amount (A) using the formula. The total interest earned is calculated by subtracting the Principal (P) from the Maturity Amount (A).
Example Calculation
Let's assume you invest ₹1,00,000 (P) in an SBI FD for 60 months (t = 5 years) at an annual interest rate of 7.0% (r = 0.07). If the interest is compounded Quarterly (n = 4), the calculation would be:
A = 100000 * (1 + 0.07/4)^(4*5)
A = 100000 * (1 + 0.0175)^(20)
A = 100000 * (1.0175)^20
A = 100000 * 1.414778
A ≈ ₹1,41,478
In this example, the Maturity Amount would be approximately ₹1,41,478. The total interest earned would be ₹1,41,478 – ₹1,00,000 = ₹41,478.
Why Use an FD Calculator?
Planning: Helps you set financial goals and understand how much you can earn.
Comparison: Allows you to compare different FD schemes or tenure options offered by SBI.
Decision Making: Aids in making informed investment choices by projecting potential returns.
Tax Implications: While this calculator doesn't compute taxes, understanding the gross interest earned is the first step before considering tax liabilities.
Always refer to the latest SBI FD interest rates and terms and conditions, as these can change. This calculator provides an estimate based on the inputs provided.
function calculateFDInterest() {
var principal = parseFloat(document.getElementById("principal").value);
var annualRate = parseFloat(document.getElementById("interestRate").value);
var tenureMonths = parseFloat(document.getElementById("tenureMonths").value);
var compoundingFrequency = document.getElementById("compoundingFrequency").value;
var resultDiv = document.getElementById("result");
// Input validation
if (isNaN(principal) || principal <= 0) {
resultDiv.innerHTML = "Please enter a valid deposit amount.";
return;
}
if (isNaN(annualRate) || annualRate < 0) {
resultDiv.innerHTML = "Please enter a valid annual interest rate.";
return;
}
if (isNaN(tenureMonths) || tenureMonths <= 0) {
resultDiv.innerHTML = "Please enter a valid tenure in months.";
return;
}
var r = annualRate / 100; // Annual interest rate as decimal
var t = tenureMonths / 12; // Tenure in years
var n; // Number of times interest is compounded per year
switch (compoundingFrequency) {
case "annually":
n = 1;
break;
case "semi-annually":
n = 2;
break;
case "quarterly":
n = 4;
break;
case "monthly":
n = 12;
break;
default:
n = 4; // Default to quarterly if something goes wrong
}
// Calculate Maturity Amount using compound interest formula
var maturityAmount = principal * Math.pow((1 + r / n), (n * t));
// Calculate total interest earned
var totalInterest = maturityAmount – principal;
// Format the results to 2 decimal places and Indian Rupee format
var formattedMaturityAmount = "₹" + maturityAmount.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
var formattedTotalInterest = "₹" + totalInterest.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
var formattedPrincipal = "₹" + principal.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
resultDiv.innerHTML = "Estimated Maturity Amount: " + formattedMaturityAmount +
"Total Interest Earned: " + formattedTotalInterest + "" +
"(Based on ₹" + principal.toFixed(2) + " deposit for " + tenureMonths + " months at " + annualRate + "% p.a.)";
}