jinwoolab logo

ROI Calculator · Return on Investment

Enter your investment and expected monthly profit to see your ROI and break-even point instantly.

Your numbers

This calculator is for reference only and does not constitute financial advice.

How it works

  • Monthly ROI = monthly profit ÷ initial investment × 100
  • Annual ROI = monthly ROI × 12 (simple, not compounded)
  • Break-even period = initial investment ÷ monthly profit (in months)

Example: investing $10,000 to earn $800 a month gives a monthly ROI of 8%, an annual ROI of 96%, and a break-even period of 12.5 months.

Getting a realistic number

  • Use profit, not revenue — subtract the running costs the investment adds (materials, staff time, fees)
  • Include everything you paid up front: equipment, setup, training, the first month of subscriptions
  • If profit ramps up over a few months, use a conservative average

FAQ

What is a good ROI?

It depends on the risk and the alternatives. Compare it with what the same money would earn elsewhere, and look at the break-even period: a shorter payback means less time with your money at risk.

Is annual ROI compounded?

No. Annual ROI here is the monthly ROI multiplied by 12, which is the usual quick estimate for small business decisions.

Simple ROI and payback formulas · checked October 18, 2026