Metric Republic / Energy & building physics / Energy Savings Simple Payback Calculator

Energy Savings Simple Payback Calculator

Estimate annual net savings, simple payback and first-year ROI for an energy investment.

Updated September 2026

How it works

Estimate annual net savings, simple payback and first-year ROI for an energy investment.

Formula:
Gross saving = energy saved·price; net saving = gross−maintenance; payback = investment/net.

Before you use the result: Simple payback ignores financing, inflation, price escalation, degradation, tax and residual value.

Practical use

Use verified material data and project geometry. Treat results as planning estimates and compare them with the energy/thermal requirements that apply to the project.

Keep units consistent with the source information.
Use project-specific densities, pack sizes and coverage rates where provided.
Round purchasing quantities to supplier packaging and delivery rules.

How to use this calculator: Energy Savings Simple Payback Calculator

Estimate annual net savings, simple payback and first-year ROI for an energy investment.

Quick workflow

Enter the project values from the latest drawing, specification or verified site measurement.
Check units, material properties, allowances and any code- or supplier-specific parameters before calculating.
Review the result together with the formula, assumptions and the related checks shown on this page.

Worked example

Example inputs: Initial investment [currency]: 12 000; Annual energy saved [kWh/year]: 8 000; Energy price [currency/kWh]: 0.25; Additional annual maintenance [currency/year]: 150.

Using the sample values built into the calculator, the calculation gives approximately: Gross annual saving: 2 000 currency/year; Net annual saving: 1 850 currency/year; Simple payback: 6.486 years.

What the result means

Calculation method: Gross saving = energy saved·price; net saving = gross−maintenance; payback = investment/net.

Before using the result: Simple payback ignores financing, inflation, price escalation, degradation, tax and residual value.

Common questions

What does this calculator do?

Estimate annual net savings, simple payback and first-year ROI for an energy investment.

Which inputs should I verify?

Key inputs to verify include: Initial investment [currency], Annual energy saved [kWh/year], Energy price [currency/kWh], Additional annual maintenance [currency/year].

Can I use this result for final design or ordering?

Use the result as a transparent planning or checking aid. Final design, code compliance, supplier selection and project-specific decisions still need to be verified where applicable. Simple payback ignores financing, inflation, price escalation, degradation, tax and residual value.

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