# How many carbon credits do I need to offset my company's emissions?

Canonical: https://senseible.earth/answers/how-many-carbon-credits-do-i-need

One carbon credit covers one tonne of CO2e. You need as many credits as the tonnes left in your claim boundary for the period after the reductions you have made, rounded up. So a company with 320 tonnes of measured emissions needs at least 320 credits, retired in its name, for that year.

## Step 1: fix the boundary and the period

Decide what the claim covers: the whole company or one site, and which scopes. A Scope 1 and 2 total is the minimum. For a carbon neutral claim under ISO 14068-1, significant indirect emissions, including relevant Scope 3, belong in the footprint too, so the number of credits can be several times larger than Scope 1 and 2 alone.

Use one reporting period, such as the financial year April to March, and the same period for the credits.

## Step 2: measure, then subtract real reductions

Calculate emissions with the GHG Protocol Corporate Standard: activity data times a published factor. Reductions count only if they show up in this period's activity data, such as fewer litres of diesel or fewer kWh. Renewable electricity lowers market-based Scope 2 only with valid certificates or contracts. Credits you have already used for another claim cannot be counted again.

## Step 3: convert tonnes to credits

1. Take residual emissions in tonnes CO2e.
2. Round up to the next whole tonne, because credits are issued in whole tonnes.
3. Some buyers add a small buffer, for example 5 percent, for data uncertainty. This is a choice, not a rule; state it if you do.
4. Retire the credits on the registry with your company name, the period and the claim in the retirement note.

## What the number does not tell you

The count is the easy part. Quality decides whether the claim holds: check the project type, vintage, any rating against the ICVCM Core Carbon Principles, and whether the credit is avoidance or removal. Under the VCMI Claims Code, a company must also show progress on its own reduction target before credits can support a claim.

## Worked example: Scope 1 and 2 for one year

- Diesel: 40,000 L x 2.68 kg CO2/L = 107,200 kg CO2 = 107.2 t
- Grid electricity: 300,000 kWh x 0.710 kg CO2/kWh = 213,000 kg CO2 = 213.0 t
- Total: 107.2 + 213.0 = 320.2 t, rounded up to 321 credits
- With an optional 5 percent buffer: 320.2 x 1.05 = 336.2 t, so 337 credits

The diesel and grid factors are CO2 factors (IPCC 2006 default and CEA version 21.0). Other gases from diesel combustion are small and not included here.

## What Senseible does here

Senseible gives you the tonnes figure to start from: Scope 1 from fuel invoices and Scope 2 from electricity bills, each line traceable to its document. It does not sell, issue or retire carbon credits for this purpose.

- [Carbon offsets vs carbon credits](https://senseible.earth/climate-intelligence/carbon-offsets-vs-carbon-credits-difference-explained)
- [Net zero vs carbon neutral](https://senseible.earth/answers/net-zero-vs-carbon-neutral)
- [What to check before buying credits](https://senseible.earth/answers/what-to-check-before-buying-carbon-credits)
- [Diesel emission factor](https://senseible.earth/emission-factors/diesel)

Sources: [ISO 14068-1:2023, Carbon neutrality](https://www.iso.org), [GHG Protocol Corporate Standard](https://ghgprotocol.org/corporate-standard), [VCMI Claims Code of Practice](https://vcmintegrity.org)

Last reviewed 2026-10-15.