Environmental ROI

Free Environmental ROI calculator with clear step-by-step results.

About Environmental ROI

Values an environmental project on two currencies at once: the cash it saves and the carbon it avoids, priced at your internal carbon price. The cost-per-tonne-abated figure is the one that lets you rank competing projects, and it goes negative when the cash savings alone justify the spend.

Formulas

Annual net benefit

Net = cost saving + tonnes avoided x carbon price - additional operating cost

Cost per tonne abated

Cost = (capex - net cash saving x life) / (tonnes per year x life)

Worked example

With the default values below, Environmental ROI returns Lifetime return on investment of 168.0%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Upfront project costminimum 0 $: 45,000 $
Annual operating cost savingminimum 0 $: 7,800 $
Annual emissions avoidedminimum 0 tCO2e: 14 tCO2e
Internal carbon priceminimum 0 $/tCO2e: 60 $/tCO2e
Project lifeaccepts 1–50: 15
Additional annual operating costminimum 0 $: 600 $

Results

Lifetime return on investment: 168.0% %
Annual net benefit including carbon value: $8,040.00
Simple payback: 5.60 years
Net cost per tonne abated: -$300.00

Step by step

1Values used
2Annual net benefit
3Cost per tonne abated
4Lifetime return on investment= 168.0 %
5Annual net benefit including carbon value= $8,040.00
6Simple payback= 5.60 years
7Net cost per tonne abated= -$300.00/tCO2e

Assumptions and limits

The result is derived only from the 6 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation or tax into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

What internal carbon price should I use?

Corporate shadow prices commonly sit between $40 and $100 per tonne. Regulated markets set their own; use your compliance price if you are exposed to one.

What does a negative cost per tonne mean?

The project pays for itself on cash savings alone, so the abatement is effectively free. Those projects should always be done first.