Investment Calculator — What Your Money Becomes

Enter Parameters

Adjust sliders or type values directly

Initial Starting Investment

Additional Monthly Contribution

Expected Annual Return

Investment Horizon

years

Real-time Calculation Ready

Adjust parameters to see instant results

AI Summary & Key Formula

Investment Calculator Quick Reference

0ms Client-Side 100% Private

Quick Answer

An investment calculator projects the future value of a starting lump sum plus regular monthly contributions, compounding the annual return monthly: FV = P × (1 + r)ⁿ + PMT × ((1 + r)ⁿ − 1) / r × (1 + r), with r the monthly rate and n the number of months. For example, $10,000 upfront plus $500 a month for 20 years at 8% a year grows to about $345,742 — $130,000 of contributions and $215,742 of returns. Use it to compare savings rates and time horizons; it assumes a steady return with contributions at the start of each month, and ignores fees, taxes and inflation.

How This Calculation Works

Values calculate dynamically in real-time as you enter figures or adjust sliders.
The equation on the right is exactly what the calculator runs — check any result by hand.

Core Equation

Future Value (Lump Sum): FV = P × (1 + r/12)^(n×12)
  P = Initial investment | r = Annual rate | n = Years (compounded monthly)

Future Value (Monthly Contributions, invested at the start of each month):
  FV = PMT × ((1 + r/12)^(n×12) − 1) / (r/12) × (1 + r/12)

Combined: Total FV = Lump Sum FV + Monthly FV
Returns = Total FV − Total Contributions

How to Use the Investment Calculator

Quick 3-step guide for accurate and fast calculations

STEP 01

Enter your initial starting investment

In the Investment Calculator, fill in Initial Starting Investment, Additional Monthly Contribution, Expected Annual Return and Investment Horizon.

STEP 02

Read your total future portfolio value

The Investment Calculator instantly shows Total Future Portfolio Value, Total Amount Invested, Total Wealth Gain (Returns) and Investment Multiplier (X), updating as you type.

STEP 03

Compare scenarios

Change Additional Monthly Contribution to see how it affects Total Future Portfolio Value, then check the formula below to verify the math.

Specific Instructions:

Enter an initial lump sum (or leave it at zero for recurring-only). Add a monthly contribution amount if you plan to invest regularly. Set your expected annual return rate and investment duration in years. The calculator shows your final portfolio value, total amount invested, and total returns. A growth chart visualises the compounding curve.

Investment Calculator Formula

The Investment Calculator uses the following formula, calculated in your browser as you change the inputs:

Future Value (Lump Sum): FV = P × (1 + r/12)^(n×12) P = Initial investment | r = Annual rate | n = Years (compounded monthly) Future Value (Monthly Contributions, invested at the start of each month): FV = PMT × ((1 + r/12)^(n×12) − 1) / (r/12) × (1 + r/12) Combined: Total FV = Lump Sum FV + Monthly FV Returns = Total FV − Total Contributions

Sources:

Worked Example: Investment Calculator

Calculations run in your browser — your inputs are never stored on our servers.Formula sources & methodology

Guide

SIP vs Lump Sum Investing: How They Compare

A lump sum puts all your money to work at once, so it tends to earn more when markets rise steadily, while a SIP (systematic investment plan) invests a fixed amount every month, which spreads your entry price and suits people investing from a monthly income. Neither is always better: lump sum wins on time in the market, and SIP wins on discipline and lower timing risk.

Guide

Simple vs Compound Interest: The Difference Explained

Simple interest is calculated only on the original principal, using SI = P × R × T ÷ 100, while compound interest is calculated on the principal plus interest already earned, using A = P(1 + r/n)^(nt). At 8% for 5 years, ₹1,00,000 earns ₹40,000 as simple interest but about ₹46,933 with annual compounding, and the gap widens every year.

Frequently Asked Questions — Investment Calculator

What rate of return should I use in an investment calculator?

Use a conservative estimate based on historical averages for your asset class. The S&P 500 has returned ~10% annually before inflation (and ~7% after inflation) over 90+ years. For diversified global equity portfolios, 7–9% is a common planning assumption. Bonds typically return 3–5%. Always model at multiple rates (pessimistic, moderate, optimistic) to stress-test your plans.

How does compound interest grow investments?

Compound interest means you earn returns not just on your original investment but also on previously earned returns. A $10,000 investment at 8% earns $800 in year 1. In year 2 it earns 8% on $10,800 = $864. This snowball effect accelerates dramatically over decades — more than half of a 30-year investment's final value often comes from compounding in the final 10 years.

Should I invest a lump sum or monthly contributions?

If you have a lump sum available, investing it all immediately is statistically better (markets rise more often than they fall). However, monthly contributions (dollar-cost averaging) reduce timing risk, fit most people's income patterns, and are psychologically easier to maintain. The best approach combines both: invest any lump sum you have now and continue monthly contributions.