Worked example

The example in the answer above covers 7.5 tonnes of CO₂e with a 10% buffer, priced at the average for all voluntary credits:

  1. Emissions to cover: 7.5 t CO₂e.
  2. Add a 10% buffer: 7.5 × 1.1 = 8.25 t.
  3. Round up to whole credits (one credit = one tonne): 9 credits.
  4. Price: All voluntary credits (market average), $6.12–$6.92 per tonne in our October 2026 snapshotSource 3. Cost: 9 × $6.12 = $55.08, up to 9 × $6.92 = $62.28.

How we calculate

  1. Credits. One carbon credit represents one tonne of CO₂ equivalent reduced or removedSource 2. We multiply your emissions by one plus the buffer you choose, then round up to a whole credit.
  2. Price. We take the average price range for the credit type you pick from our latest carbon credit price snapshot. For the market average and the main forest types, the range comes from Sylvera’s Q3 2026 data on credits retiredSource 3. For other types it runs from the lower to the higher of the 2023 and 2024 average transaction prices reported by Ecosystem MarketplaceSource 1.
  3. Cost. We multiply the number of credits by the low and high price to give a cost range.

The buffer is your choice. It adds a margin in case your estimate is low. We don’t recommend a particular size, and 0% is fine if you trust your estimate.

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Average prices used by the calculator (USD per tonne), as of October 2026
CategoryKindLow (USD/t)High (USD/t)What the range is, and when
All voluntary credits (market average)Mixed6.126.92Average price per credit retired: $6.12 in 2026 so far (Q1–Q3), $6.92 in Q3 2026 (Sylvera)
Renewable energyAvoidance2.673.92Average transaction price: $3.92 in 2023, $2.67 in 2024 (Ecosystem Marketplace, Table 3)
Chemical processes and industrial manufacturingAvoidance3.664.10Average transaction price: $4.10 in 2023, $3.66 in 2024 (Ecosystem Marketplace, Table 3)
REDD+ (forest protection)Avoidance3.567.75Average price per credit retired in Q3 2026: $3.56 rated BB or lower, $7.75 rated BBB or higher (Sylvera)
Waste disposalAvoidance6.727.46Average transaction price: $7.46 in 2023, $6.72 in 2024 (Ecosystem Marketplace, Table 3)
Household and community devices (incl. cookstoves)Avoidance7.307.71Average transaction price: $7.71 in 2023, $7.30 in 2024 (Ecosystem Marketplace, Table 3)
AgroforestryMixed11.5814.11Average transaction price: $11.58 in 2023, $14.11 in 2024 (Ecosystem Marketplace, Table 4)
Improved forest management (IFM)Mixed12.7921.07Average price per credit retired in Q3 2026: $12.79 rated BB or lower, $21.07 rated BBB or higher (Sylvera)
Afforestation, reforestation and revegetation (ARR)Removal12.8023.47Average price per credit retired in Q3 2026: $12.80 rated BB or lower, $23.47 rated BBB or higher (Sylvera)
BiocharRemoval160.00160.00Average transaction price in 2024 was over $160 (Ecosystem Marketplace report summary); no range published
All reduction creditsAvoidance4.054.64Average transaction price: $4.64 in 2023, $4.05 in 2024 (Ecosystem Marketplace, Table 7)
All removal creditsRemoval17.2819.50Average transaction price: $17.28 in 2023, $19.50 in 2024 (Ecosystem Marketplace, Table 7)

As of Oct 2026 · Sources: [3] Carbon Market Data Snapshot: Q3 2026; [1] State of the Voluntary Carbon Market 2025: Meeting the Moment, Renewing Trust in Carbon Finance

Limitations

A guide, not a quote

The prices are averages of deals reported to Ecosystem Marketplace’s survey, which it describes as lower bounds for the whole marketSource 1. Retail prices for small purchases, specific projects and recent vintages can be higher or lower. Use the estimate to plan a budget, then compare sellers’ prices for the credits you actually want.

To work out your emissions first, use the carbon footprint calculator or the flight emissions calculator. Our guide to where to buy carbon credits compares sellers, and all our calculators are on the tools page.