Cost and catch
Yes. Free for companies under 500 employees, with no trial period and no card. Murmurate is a non-profit, so there is no commercial pressure to put a paywall in later. Larger organisations pay, and that is what funds the free tier.
We want you measuring and communicating your footprint so everyone can improve together. You keep control of whether it is published, and nothing is shared without your say-so. The more companies publish, the less everyone has to guess about their supply chain, which is the whole point.
Because carbon accounting does not need another expensive tool. It needs enough companies measuring that the data becomes useful. Charging the smaller ones works against that.
What it does
A Scope 1, 2 and 3 footprint, excluding some harder-to-calculate downstream emissions (coming in Q4 2026), calculated from your own data, with every figure showing its source, emission factor and method. You can hand it to an auditor without rebuilding it.
It follows the GHG Protocol and uses published emission factors, including government-issued data, WMBC-funded electricity factors and EXIOBASE. Where we estimate, we say so: reported figures and estimates are never silently mixed.
That depends on how tidy your data is more than on the software. Most of the work is gathering energy bills, spend data and supplier lists. The calculator is the quick part.
Yes. Most people measuring a footprint for the first time are doing it because a customer or a tender asked. You do not need to understand the GHG Protocol to the letter to build a valid footprint.
The open database
The open database your footprint can join: 17,000+ company footprints, free for anyone to search. It is run by the same non-profit, and it is how your suppliers' numbers reach you and yours reach your customers.
No. Publishing is a choice. Most companies do, because a public record answers the supplier questionnaires before they are sent, but the calculator works either way.
Only those you share it with. All your data stays yours; a shared or published footprint shows the headline figures and how they were reached. The more you disclose, the better your transparency score and the more potential customers will see your data.
Suppliers and Scope 3
Scope 3 is mostly other companies' emissions, and industry averages are guesswork. Search Mycelium for suppliers already publishing, invite the ones who are not, and every supplier who joins replaces a guess with a real number.
You will still get a complete footprint using estimates, and you will see where your biggest gaps are. The invite loop is how those estimates turn into real figures over time.
Practical
Murmurate is the successor to the Advanced Business Carbon Calculator and is backwards compatible with it. Upload your spreadsheet and you will see the same footprint from the same inputs.
Murmurate Digital Limited, a UK non-profit company limited by guarantee. We created the OpenCCF data model with partners including SME Climate Hub and the Carbon Accounting Alliance, and we are members of the Alliance ourselves.
Some, and we keep it low. We are cloud-hosted with central computing running in Stockholm at roughly 20 gCO₂/kWh, about 95% below the default US region, and we aggressively cache the tool to ensure the shortest and lowest-energy return-trip possible. That is a location and architecture choice, no offsets are involved. Roughly, a full report created in one 45-minute sitting comes to about 5 to 10 grams of CO₂e (about as much as a typical short email), and nearly all of that is the client computer. The computing Murmurate uses to run the platform and calculations, plus the network infrastructure used to communicate between the server and your computer, comes to about a gram.