Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Annual emissions reduction
154.9
Current fleet emissions
210.5
EV fleet emissions
55.6
Percent reduction
74%
Reduction per vehicle
6.20
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter number of vehicles.
- 2Enter annual miles per vehicle.
- 3Enter current fleet fuel economy (mpg).
- 4Enter ev efficiency (kWh/mile).
- 5Enter grid emission factor (kg CO2e/kWh).
- 6Read your annual emissions reduction on the right — it updates as you type.
- 7Hit Share to keep the scenario or send it to someone.
About this calculator
Switching fleet vehicles to electric doesn't zero out emissions — it shifts them upstream to the grid. This calculator compares tailpipe emissions from your current fleet's fuel consumption against the emissions of charging an equivalent EV fleet on your local grid, so you get a real net reduction number instead of a marketing claim. It accounts for the EV's efficiency (kWh per mile) and your grid's carbon intensity, which is the variable people most often ignore. In a clean grid area the delta is dramatic; in a coal-heavy grid the reduction can be surprisingly modest, sometimes under 30%. Fleet managers use this to size the emissions-reduction line in ESG reports and to decide whether to time an EV rollout with a green-tariff or on-site solar purchase that improves the charging carbon intensity.
Worked example
Using the values the calculator loads with:
Inputs
- Number of vehicles: 25
- Annual miles per vehicle: 18000
- Current fleet fuel economy: 19 mpg
- EV efficiency: 0.32 kWh/mile
- Grid emission factor: 0.386 kg CO2e/kWh
Results
- Annual emissions reduction: 154.9
- Current fleet emissions: 210.5
- EV fleet emissions: 55.6
- Percent reduction: 74%
- Reduction per vehicle: 6.2
What each field means
Inputs
- Number of vehicles
- The number of vehicles used in the calculation. Starts at 25 so you have a working example on load.
- Annual miles per vehicle
- The annual miles per vehicle used in the calculation. Starts at 18000 so you have a working example on load.
- Current fleet fuel economy (mpg)
- The current fleet fuel economy used in the calculation, measured in mpg. Starts at 19 mpg so you have a working example on load.
- EV efficiency (kWh/mile)
- The ev efficiency used in the calculation, measured in kWh/mile. Starts at 0.32 kWh/mile so you have a working example on load.
- Grid emission factor (kg CO2e/kWh)
- The grid emission factor used in the calculation, measured in kg CO2e/kWh. Starts at 0.386 kg CO2e/kWh so you have a working example on load.
Results
- Annual emissions reduction
- Returned as a whole number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Current fleet emissions
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- EV fleet emissions
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Percent reduction
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Reduction per vehicle
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why is the reduction lower than I expected?
If your grid factor is high — coal-heavy states run 0.6-0.8 kg CO2e/kWh — the upstream emissions from charging eat into the savings. A fleet in a clean grid like California or the Northwest can see 70-80% reduction; a fleet in a coal-heavy Midwest grid might only see 30-40%.
Does this include vehicle manufacturing emissions?
No, this is operational (tailpipe/charging) emissions only. EV manufacturing carries a higher embodied carbon footprint than ICE vehicles, mostly from battery production, but that's typically recovered within 1-2 years of driving given the operational savings shown here.
How do I improve the reduction number further?
Pair the EV rollout with a green tariff, on-site solar, or a time-of-charge program that shifts charging to hours when the grid is cleaner (usually midday with solar-heavy grids). Each of these lowers your effective grid factor input and increases the delta.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Fleet Electrification Emissions Delta Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/fleet-ev-emissions-delta
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/fleet-ev-emissions-delta" target="_blank" rel="noopener">Fleet Electrification Emissions Delta Calculator — RevenueLab</a> (2026).</p>
Source: [Fleet Electrification Emissions Delta Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/fleet-ev-emissions-delta) (2026).