Cloud Carbon Footprint Calculator
Estimate the emissions of a cloud estate from vCPU hours, PUE and grid carbon intensity, and what a greener region saves.
About Cloud Carbon Footprint Calculator
Server power is not proportional to load: a vCPU draws a substantial idle baseline and rises toward a loaded ceiling, so utilisation is interpolated between the two rather than multiplied. The resulting kilowatt-hours are scaled by PUE to account for cooling and distribution losses, then converted with the grid intensity of the specific region the workload runs in. Region choice usually dominates every other sustainability lever — the same workload can emit eight times more on a coal-heavy grid than on a hydro-backed one, and moving it costs nothing but latency. These are order-of-magnitude planning estimates; use your provider's own carbon reporting for anything you disclose.
Formula
Cloud Carbon Footprint
watts per vCPU = idle + (loaded − idle) × utilisation; kWh = (compute watts + storage watts) × hours ÷ 1000 × PUE; kgCO2e = kWh × grid intensity ÷ 1000 × (1 + embodied uplift).
- PUE
- Power usage effectiveness — facility power divided by IT power
- grid intensity
- Grams of CO2 equivalent emitted per kilowatt-hour on that grid
- embodied uplift
- Share added for manufacturing emissions amortised over hardware life
Worked example
With the default values below, Cloud Carbon Footprint Calculator returns Monthly Carbon Footprint of 585.0. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Total vCPUs runningaccepts 0–500,000 vCPU
- 800 vCPU
- Average CPU utilisationaccepts 0–100 %
- 40 %
- Idle power per vCPUaccepts 0–50 W
- 0.71 W
- Fully loaded power per vCPUaccepts 0–100 W
- 3.5 W
- Storage provisionedaccepts 0–100,000 TB
- 120 TB
- Power per terabyte of storageaccepts 0–20 W/TB
- 1.2 W/TB
- Hours in the monthaccepts 1–744 hours
- 730 hours
- Provider PUEaccepts 1–3 ratio
- 1.135 ratio
- Grid carbon intensity of your regionaccepts 0–1,200 gCO2e/kWh
- 400 gCO2e/kWh
- Intensity of a low-carbon regionaccepts 0–1,200 gCO2e/kWh
- 45 gCO2e/kWh
- Embodied carbon upliftaccepts 0–100 %
- 10 %
- Matched renewable energyaccepts 0–100 %
- 0 %
Results
- Monthly Carbon Footprint
- 585.0 kg CO2e
- Annual Footprint
- 7.02 t CO2e
- Monthly Electricity Drawn
- 1,330 kWh
- Footprint After Renewable Matching
- 585.0 kg CO2e
- Footprint in a Low-Carbon Region
- 65.8 kg CO2e
- Reduction from Moving Region
- 88.8%
- Tree-Years to Absorb a Year of This
- 334 tree-years
Step by step
- 1Values used
- 2Cloud Carbon Footprint
- 3Monthly Carbon Footprint= 585.0 kg CO2e
- 4Annual Footprint= 7.02 t CO2e
- 5Monthly Electricity Drawn= 1,330 kWh
- 6Footprint After Renewable Matching= 585.0 kg CO2e
- 7Footprint in a Low-Carbon Region= 65.8 kg CO2e
- 8Reduction from Moving Region= 88.8
Assumptions and limits
- The result is derived only from the 12 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax or compounding frequency 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
How is Cloud Carbon Footprint calculated?
watts per vCPU = idle + (loaded − idle) × utilisation; kWh = (compute watts + storage watts) × hours ÷ 1000 × PUE; kgCO2e = kWh × grid intensity ÷ 1000 × (1 + embodied uplift). Server power is not proportional to load: a vCPU draws a substantial idle baseline and rises toward a loaded ceiling, so utilisation is interpolated between the two rather than multiplied. The resulting kilowatt-hours are scaled by PUE to account for cooling and distribution losses, then converted with the grid intensity of the specific region the workload runs in.
Why does Cloud Carbon Footprint matter?
Region choice usually dominates every other sustainability lever — the same workload can emit eight times more on a coal-heavy grid than on a hydro-backed one, and moving it costs nothing but latency. These are order-of-magnitude planning estimates; use your provider's own carbon reporting for anything you disclose.
What values do I need to enter?
This calculator takes 12 inputs: Total vCPUs running, Average CPU utilisation, Idle power per vCPU, Fully loaded power per vCPU, Storage provisioned, Power per terabyte of storage, Hours in the month, Provider PUE, Grid carbon intensity of your region, Intensity of a low-carbon region, Embodied carbon uplift, Matched renewable energy. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
Why does the answer differ from my provider's carbon dashboard?
Providers apply market-based accounting that nets off the renewable energy certificates they buy, and they use measured rather than modelled server power. This calculator is location-based and model-driven, which is the more conservative view and the one most useful for comparing regions.