How to create a saving calculator.
💰 How to Create a Saving Calculator Function (Installment Savings) Have you ever wondered: “If I deposit $300 every month at 4% interest, how much will I have after one year?” In this post, we’ll learn how to build a Saving Calculator Function right inside your own programmable calculator app — so you can find the answer instantly without opening a bank app. 🧩 1. Understanding the Saving Formula The general formula for calculating the future value of monthly savings (ordinary annuity) is: FV = PMT × ((1 + r)^n - 1)/r where: PMT = monthly deposit r = monthly interest rate (annual rate ÷ 12 ÷ 100) n = number of months This version assumes the deposit is made at the end of each month, which is how most banks calculate regular savings plans. 💻 2. Creating the Function (End-of-Month Deposit) Here’s the SimpleMath code version for your programmable calculator: def saving(principal, annualRate, months){ var monthlyRate = annualRate / 12/ 100; var total = p...