Calculate an offset procurement requirement from a residual emissions balance, the percentage eligible for offsetting, credits already held, and a delivery-risk buffer. Unlike a footprint calculator, this tool focuses on the remaining purchase quantity for a defined claim period.
Purchase requirement = max(0, Eligible residual emissions − Usable held credits) × (1 + Buffer %), where Usable held credits = Held credits × (1 − Loss %).
The main result is the additional number of credits to procure after adjusting held inventory for expected invalidation or delivery loss and adding the selected buffer.
A credit count alone does not establish eligibility. Confirm project type, vintage, geography, registry status, authorization, and retirement requirements.
For 5,000 t eligible residual emissions, 1,200 held credits with 2% expected loss leave 1,176 usable credits. The 3,824-credit shortfall plus a 5% buffer requires 4,015.2 credits.
The loss input models credits that may be invalidated, delayed, rejected, or otherwise unavailable for retirement.
It is the share of residual emissions that the applicable program or claim permits you to address with offsets.
No. Surplus held credits produce a zero purchase requirement rather than a negative order.
No. This input is a procurement contingency; project-level permanence buffer rules are separate.
Planning can use decimals, but registry issuance and purchasing conventions may require whole credits.
| Variable | Meaning | Unit |
|---|---|---|
| Residual emissions | Emissions remaining after direct reductions | t CO₂e |
| Eligible share | Residual amount permitted for offsetting | % |
| Usable held credits | Inventory after expected loss | credits |
| Delivery buffer | Extra procurement above the shortfall | % |