Carbon Offset Calculator
Calculate the cost to offset a given carbon footprint through different verified offset programmes.
Did this tool work for you?
How to use this calculator
- 1
Enter the total tonnes of CO₂ you want to offset.
- 2
Select the type of offset programme from the dropdown.
- 3
Review the cost range, the built-in quality label and the points to check for that programme type.
- 4
Treat the range as a rough budget and ask any seller for its own price and documentation.
Frequently asked questions
How is the cost calculated?
This tool multiplies tonnes by a low and a high price per tonne for the programme type you select. 5 tonnes of the Gold Standard Forestry type at $15 to $30 gives $75 to $150. Results are rounded to whole dollars, so 0.5 tonnes at the same range shows $8 to $15.
Where do the prices come from?
They are ranges built into this tool, one per programme type, and are not live quotes. Real values vary by project, year and supplier, and a seller’s actual price may fall outside the range. The tool does not look up or compare any provider.
What do the quality label and the notes mean?
The “Built-in Quality Label” (High or Medium) and the two note lines are short descriptions written into the tool for each type. They are not ratings from an independent body. The notes list things to check, such as the certifying standard and how long carbon stays stored.
What is the trees equivalent?
Tonnes × 1,000 ÷ 21, rounded, which treats one tree as absorbing 21 kg of CO₂ in a year. 5 tonnes becomes 238 trees. The number is the same for every programme type, because it depends on the tonnes alone. It is a unit conversion, not a statement about what planting would achieve.
Does it tell me which type to buy?
No. It reports a price range and a few points to check for each type and leaves the decision to you. The tool does not endorse any scheme, registry or seller.
Can I enter fractions of a tonne or zero?
Yes. Decimals are accepted, zero gives $0 for both estimates, and negative entries are treated as zero. Costs are not scaled for bulk discounts.
Where can I get a tonnage to enter?
From your own calculation, for example the footprint calculator. This tool does not estimate emissions. It also does not verify that any purchase cancels emissions; that is a question about the project and its accounting.
Carbon offset cost calculator by programme type
How to use the carbon offset calculator
Use this carbon offset calculator to estimate how many tonnes of CO₂ you need to offset and the approximate cost to do so. Enter your annual emissions from flights, driving, home energy, and diet above. Results show the total carbon footprint and the offset cost at current market rates. Free and instant.
How the carbon offset calculator works
The carbon offset calculator applies IPCC and DEFRA emission factors to your lifestyle inputs to estimate your carbon footprint in tonnes of CO₂ equivalent. It then multiplies by a carbon credit price (sourced from voluntary carbon markets) to estimate the offset cost. All calculations run locally in your browser.
Turning tonnes into a price range
If you already know how many tonnes of CO₂ you want to account for, the calculator shows what that would cost under five categories of programme. Each category carries a low and a high price per tonne, so the result is a range and not a single number. The price ranges are the figures built into this tool and are illustrative; real values vary by supplier, project and year.
| Programme type | Low $/t | High $/t | Built-in quality label |
|---|---|---|---|
| Gold Standard Forestry | 15 | 30 | High |
| Renewable Energy | 3 | 10 | Medium |
| Direct Air Capture (DAC) | 250 | 600 | High |
| Soil Carbon | 10 | 50 | Medium |
| Blue Carbon (Mangroves) | 20 | 50 | High |
Worked example: five tonnes
Five tonnes costs $75 to $150 under the forestry type, $15 to $50 under renewable energy, $50 to $250 under soil carbon, $100 to $250 under mangroves and $1,250 to $3,000 under direct air capture. The tree equivalent is 238 for every row. The spread from $15 to $3,000 for the same tonnage comes entirely from the price ranges in the table, which differ because the programmes work in different ways.
| Programme type | Low estimate | High estimate |
|---|---|---|
| Gold Standard Forestry | $75 | $150 |
| Renewable Energy | $15 | $50 |
| Soil Carbon | $50 | $250 |
| Blue Carbon (Mangroves) | $100 | $250 |
| Direct Air Capture | $1,250 | $3,000 |
Worked example: smaller and larger amounts
Half a tonne under the forestry type comes to $8 to $15 (the low figure of $7.50 rounds up) and 24 trees. A larger 12.4 tonnes under direct air capture comes to $3,100 to $7,440 and 590 trees. Costs scale in a straight line with tonnes, so doubling the tonnage doubles both ends of the range.
| Tonnes | Type | Low | High | Trees equivalent |
|---|---|---|---|---|
| 0.5 | Gold Standard Forestry | $8 | $15 | 24 |
| 12.4 | Direct Air Capture | $3,100 | $7,440 | 590 |
Reading the notes
Each type comes with a short note and a list of points to check. For renewable-energy credits the tool flags that additionality, whether the project would have happened anyway, is debated. For soil carbon it flags that stored carbon can be released again. These are prompts for your own questions to a seller, not a verdict on any scheme. The same tonnage can therefore carry very different price ranges, and a seller’s own quote may sit inside or outside the built-in range.
Limits
The tool does not find, compare or rate sellers, and it does not verify that any purchase cancels emissions. It also does not estimate your tonnage. Treat the output as a rough budget range and ask any seller for its own price and documentation.
Learn more from an authoritative source:
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Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →