loan-emi-calculator-api/routeService.js

A simple API to calculate Loan EMI using Node.js and Express

function calculateEMI(principal, annualRate, tenure) {
    if (principal <= 0 || annualRate < 0 || tenure <= 0) {
        return { error: "Invalid input values" };
    }

    const monthlyRate = annualRate / 12 / 100;
    const emi = (principal * monthlyRate * Math.pow(1 + monthlyRate, tenure)) /
        (Math.pow(1 + monthlyRate, tenure) - 1);

    return {
        loanAmount: principal,
        annualInterestRate: annualRate,
        tenureMonths: tenure,
        emi: emi.toFixed(3)
    };
}
exports.calculate_emi = async (principal, annualRate, tenure) => {
    try {
        if (principal === undefined) {
            return { error: "Principal are required" };
        }
        if (annualRate === undefined) {
            return { error: "AnnualRate are required" };
        }
        if (tenure === undefined) {
            return { error: "Tenure are required" };
        }
        const result = calculateEMI(principal, annualRate, tenure);
        return { status: 1, message: "Emi Calculated Successfully", result }
    } catch (error) {
        console.log(error);

        res.status(500).json({ message: "Error fetching distance", error: error.message });
    }
};