ROI & Payback Calculator

Measure the return on an investment and how long it takes to pay back. Periodic mode: enter an upfront cost and a recurring return (monthly or yearly) to get the payback period and ROI over a horizon. One-shot mode: enter a cost and a final value plus the holding period to get the simple ROI and annualized (CAGR-style) return. Runs entirely in your browser.

Investment cost

Return per period

Period is

Horizon (periods)

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Enter cost and return to see payback.

Payback = cost ÷ return-per-period (how long to recoup the investment). Simple ROI = (total return − cost) ÷ cost. Annualized ROI (CAGR) = (final value ÷ cost)^(1 ÷ years) − 1. Periodic mode assumes a constant return each period with no reinvestment or discounting; one-shot mode uses the compound growth formula. Negative ROI means a loss. Runs locally — for general guidance, not financial advice.