Carbon Footprint & Emission Factor API
Turn any activity, spend, shipment or flight into kg CO₂e from open, authoritative data — UK DEFRA, US EPA, Ember and IPCC. Get live electricity grid carbon intensity for GB, US & EU, and a “best time to run” signal that cuts both energy cost and carbon. Every response cites its source, year, licence and a data-quality grade.
Everything you need to measure carbon
One API across the questions carbon-accounting and carbon-aware apps actually ask — from a fuel receipt to a supply-chain dollar to a live grid signal.
Activity → CO₂e
Fuels, electricity, transport, materials, waste and more. Automatic unit conversion, region-aware factor selection, full provenance.
Spend-based Scope 3
Dollar spend + industry/NAICS → CO₂e using US EPA USEEIO, inflation-adjusted to a common year. The hardest part of Scope 3, made simple.
Freight & logistics
Weight × distance × mode → CO₂e per ISO 14083 / GLEC, over DEFRA freight factors (road, rail, sea, air).
Flights with radiative forcing
Airport-to-airport CO₂e with a configurable radiative-forcing multiplier — the honest number the “official” calculators refuse to expose.
Refrigerant / F-gas GWP
Global Warming Potential and CO₂e for any refrigerant or gas across IPCC AR4/5/6; blends mass-weighted from components.
Live grid intensity
Real-time electricity carbon intensity for GB (NESO), US balancing authorities (EIA) and EU bidding zones (ENTSO-E), from the live generation mix.
Best time to run
The cleanest upcoming window to run a load — shift compute, charging or heating to cut carbon and energy cost together.
Search & version factors
Search 2,892 factors, fetch any by id, and see year-over-year history & diffs — reproducibility for CSRD / audit.
Simple GET requests, structured JSON
No SDK required. Query params in, cited JSON out — agent- and MCP-friendly.
# 40 litres of diesel → kg CO₂e GET /estimate?activity=diesel&amount=40&unit=litres { "co2e_kg": 106.462, "factor": { "source": "UK DEFRA/DESNZ 2025", "license": "OGL-3.0", "data_quality": { "tier": "A" } } }
# cleanest 3h window to run a load (GB) GET /grid/best-window?duration=3&zone=GB { "best_window": { "avg_gco2_per_kwh": 88.7 }, "savings_vs_average_pct": 48.7, "recommendation": "Run 3h from 12:30 UTC — ~49% lower carbon" }
# $50k of cloud hosting spend (2024) → Scope 3 CO₂e, US EPA USEEIO GET /estimate/spend?amount=50000&category=cloud%20hosting&year=2024 { "co2e_kg": 4338.2, "naics": "518210", "notes": ["matched category → NAICS 518210", "inflation-adjusted 2024 → 2022 USD"], "factor": { "source": "US EPA Supply Chain GHG Emission Factors v1.3 (USEEIO)", "license": "US-PD" } }
All 17 endpoints
Every endpoint is a GET with query params, returning JSON. Open the interactive reference →
| Endpoint | What it does |
|---|---|
| GET /estimate | Activity + amount → kg CO₂e |
| GET /estimate/spend | US $ spend + category/NAICS → kg CO₂e (Scope 3) |
| GET /estimate/freight | Weight + distance + mode → kg CO₂e (ISO 14083/GLEC) |
| GET /estimate/flight | Airports/distance → kg CO₂e, configurable radiative forcing |
| GET /gwp | Refrigerant/F-gas → GWP & CO₂e (IPCC AR4/5/6) |
| GET /grid/current | Live grid intensity — GB, US & EU zones |
| GET /grid/forecast | Half-hourly GB grid forecast (up to 48h) |
| GET /grid/best-window | Cleanest window to run a load (GB) |
| GET /footprint/time-weighted | Hourly usage profile → time-of-use CO₂e (GB) |
| GET /grid-intensity | Annual grid intensity — 213 countries + US subregions |
| GET /factors/search | Full-text search across the factor catalogue |
| GET /factors | One factor by id, with full provenance |
| GET /factors/history | Year-over-year values for a factor (2023–2025) |
| GET /factors/diff | Change in a factor between two editions |
| GET /industries/search | Find US NAICS industries + kg CO₂e/USD |
| GET /taxonomy | Valid categories, units, regions & years |
| GET / | Service metadata & endpoint index |
Built on open, authoritative data
No relicensed black boxes. Every response returns the exact source, year and licence behind the number, plus a transparent A–C data-quality grade.
Start free, scale when you’re ready
Free tier to evaluate every endpoint. Paid plans from $25/mo with flat, transparent pricing — no seats, no sales calls.