Built on Gold Standard Methodology

The carbon tools your spreadsheet can't replace

Project developers and consultants use The Carbon Workbench to run biochar yields, model project feasibility and check footprints - all built on verified methodology, all in one place.

Try a tool without signing up Not a project developer? Get your personal score →
Verified under
Gold Standard Verra VCS BSI PAS 2060 ICROA
Biochar Analysis - 1,000 kg Live
Biochar yield
280
kg produced
Carbon locked
196
kg C stable
Gross CO₂e
0.719
tCO₂e gross
Net verified
0.611
tCO₂e net
Dry mass
850 kg
Biochar
280 kg
Carbon
196 kg
Net CO₂e
611 kg
GS Cookstoves AFR£11.80+0.40· GS Safe Water£13.20+0.20· Verra VCS REDD+£6.50−0.30· Puro Biochar EU£89.00+2.00· Verra VM0044£72.00-· GS Solar S.Asia£8.40−0.10· GS Cookstoves AFR£11.80+0.40· GS Safe Water£13.20+0.20· Verra VCS REDD+£6.50−0.30· Puro Biochar EU£89.00+2.00· Verra VM0044£72.00-· GS Solar S.Asia£8.40−0.10
17Professional tools
3Standards - GS, Verra, IPCC
£0To get started

The tool suite

Professional tools for
serious carbon work

Built for project developers, consultants and carbon teams. Free tools to get started - Pro unlocks feasibility modelling, project economics and PDF exports.

Free forever
Biochar calculator, carbon footprint analyser, CO₂e converter, water project calculator. No time limit, no card needed.
Pro - £49/mo
Feasibility, cookstove, solar, borehole and forestry tools, plus branded exports, share links and embeddable calculators.
New way to start
Not sure which tool you need first?
Use Project Intake to answer a few quick questions and get a recommended starting point based on your project type, stage and goal.
Open Project Intake →
Free

Biochar Carbon Calculator

Runs the full biomass → biochar → carbon → CO₂e chain. Tweak yield, moisture, permanence discount and process emissions and the numbers update instantly. Includes sanity-check ratios so you can spot if something's off before you share it.

Open Biochar Calculator →
1,000 kg woody biomass
Dry mass850 kg
Biochar produced238 kg
Carbon in biochar167 kg
Gross CO₂e0.611 t
Net verified0.494 tCO₂e
Free

Carbon Footprint Analyser

Scope 1, 2 and 3 for your organisation, built around BSI PAS 2060. Breaks down emissions by source and gives you a straight offset cost estimate at Gold Standard pricing. Useful for ESOS reports and CarbonZero assessments.

Open Footprint Analyser →
50 person organisation / yr
Gas heating8.2 t
Electricity16.6 t
Flights7.0 t
Commuting17.3 t
Offset cost @ £12/t £594/yr
Pro

Project Feasibility Modeller

Plug in household count, credit price and project life and you get annual credit volumes, total revenue and a simple ROI. Useful for sense-checking a project before you spend money on validation, or putting numbers together for a funder.

Open Feasibility Modeller →
5,000 household cookstove project
Annual credits12,000 tCO₂e
Annual revenue£144k
10-yr revenue£1.44M
Total costs£650k
Net profit£790k
Pro

Solar Energy Credit Calculator

Enter system capacity, peak sun hours and the local grid emission factor and get annual MWh generation, tCO₂e credits and lifetime revenue. Presets for West Africa, East Africa, South Asia, SE Asia and Latin America - the regions where most Gold Standard solar projects are developed.

Open Solar Calculator →
500 kWp solar project · West Africa
Annual generation657 MWh
Grid EF (W.Africa)0.82 t/MWh
Annual credits539 tCO₂e
Annual revenue @ £12/t£6,468
20-yr lifetime revenue£129k
Pro

Forestry & ARR Calculator

Estimate credits from afforestation, reforestation and revegetation projects under Verra VM0047 v1.1 - the new ICVCM-approved standard. Set hectares, forest type, permanence buffer and leakage deduction and see net annual credits with each deduction broken out line by line.

Open Forestry Calculator →
500 ha tropical dry forest · VM0047
Gross sequestration3,000 tCO₂e
Permanence buffer (15%)−450 tCO₂e
Leakage (10%)−255 tCO₂e
Net annual credits2,295 tCO₂e
30-yr revenue @ £15/t£1.03M
Pro

Verification Cost Estimator

The only tool of its kind. Choose project type and standard, enter your annual credit volume and price, and get an itemised breakdown of validation costs, annual verification fees, registry charges, net year-1 revenue and break-even timeline. Saves hours of VVB quote-gathering in early project planning.

Open Verification Costs →
10,000 tCO₂e/yr cookstove · Gold Standard
Gross annual revenue£120,000
Validation (one-off)£18,000
Annual verification£9,000
Net year 1£87,000
Break-even0.2 years

Try it now

Have a play - no sign-up needed

Adjust the sliders and see what happens. Create an account when you want to save your numbers or access the Pro tools.

Inputs
Biomass input (kg)
kg wet
Moisture15%
Biochar yield28%
Carbon content70%
Permanence discount10%
Results
Net CO₂e Sequestered
-
tCO₂e (net, verified)
Open full Biochar Calculator →
Free · No sign-up · 2 minutes

Not a project developer?
Calculate your personal
Carbon Score

A data-driven personal footprint calculator covering 8 lifestyle categories - home energy, flights, car, food, shopping, digital, activity and more. Get a score, track your progress over time, and see exactly what would make the biggest difference.

Carbon Score andActivity Score - both 0-1000
24 achievements including Ground hugger, Planet plate, WHO Champion
"What if I went vegan / switched to EV / cycled to work?" scenarios
Track your score over time - see if you're improving
Get my Carbon Score →
Score preview
Carbon Score
340
/ 1000
Activity Score
680
/ 1000
Carbon Score vs UK average340 vs 520
0 best520 UK avg1000
Badges earned
Ground hugger
WHO champion
Green power
Climate champion
UK average is 520 · 2050 target is 125 · Your score updates in real time

No black boxes

You can see exactly where the numbers come from

Every emission factor has a source. Every formula is documented. Change any input and you see the effect immediately - which matters when someone asks you to justify a figure.

// Biochar carbon chain
dry_mass = input × (1 − moisture)
biochar = dry_mass × yield_pct
carbon_kg = biochar × carbon_pct
gross_co2e = carbon_kg × 3.667
net_co2e = gross × (1−process) × (1−perm)
// C→CO₂ molecular weight ratio
01
Verified emission factors
Factors pulled from IPCC AR6, UK DESNZ 2024 and Gold Standard-approved databases. We update them annually and note when we do.
02
Permanence discounting
Biochar stability is rated by H:C molar ratio. Permanence buffers follow Puro.earth and Gold Standard requirements - not made up.
03
Conservative defaults
We've set defaults at the cautious end of the range. You can change them, but they're there so your first result isn't embarrassingly optimistic.
04
Built by people who do this
Developed alongside carbon project developers with over 20 years of Gold Standard and CDM delivery behind them.

Learn and apply

Understand the market, the standards and the practical next step

The Learn section explains registries, verification, pricing, project design and embeds in plain English. It is there for developers, consultants and teams who want clearer context before they start modelling.

Start with a guide, understand the trade-offs, then move into the calculator, embed or intake flow that fits what you are trying to do.

Open the Learn hub →

Embeddable Carbon Tools

Embed carbon tools on your website without building the tooling yourself.

The Carbon Workbench includes embeddable calculators, impact counters, project maps and lead-generation widgets for public websites, client portals and investor pages. Start with the embed docs, then use the supporting guides to see how these tools fit into real carbon-market use cases.

Pricing

Free to start. £49/mo when you need more.

The free tools are the real thing, not a watered-down demo. Upgrade to Pro when you need feasibility modelling, cookstove, solar, borehole or forestry screening, branded exports and embeddable tools.

Free
For individuals & small teams exploring carbon tools
£0forever
  • Biochar Carbon Calculator
  • Carbon Footprint Analyser
  • CO₂e Unit Converter
  • Safe Water Project Calculator
  • Methodology Selector
  • Personal Carbon Score
  • Unlimited saves (free tools)
Start free
Enterprise
For commercial carbon teams generating and qualifying client opportunities
£299/ month
  • Everything in Pro
  • Lead-generating embeddable calculators
  • Sales pipeline and opportunity screening
  • Branded proposals and team access
  • Account-level embed visibility and lead signal
  • Priority onboarding support
Explore Enterprise →

How we compare

Why not just use a spreadsheet?

You can. But you'll spend a day building it, someone will question the emission factors, and you'll have to rebuild it every time something changes.

Feature Carbon Workbench Spreadsheet Enterprise GHG software
Gold Standard / Verra methodology-
Biochar, solar & forestry calculators--
Project feasibility modellingManual-
Verification cost estimator--
Shareable project links--
Methodology selector-Limited
Free tier-
Embeddable calculators--
Starting price£0£0£500+/mo

FAQ

Sensible questions

Answered honestly, with a few newer ones around embeds and team use.

How accurate are the calculations?

+

All calculations use emission factors from IPCC AR6, UK DESNZ 2024, and Gold Standard approved databases. The biochar methodology is aligned with Puro.earth and Gold Standard permanence requirements. These are estimation tools - for formal credit issuance you'll still need independent verification.

Can I use these numbers in a Gold Standard submission?

+

The Carbon Workbench uses Gold Standard aligned methodology and is a strong starting point for project planning and feasibility. For formal submissions, you'll need a registered auditor to verify final numbers - but our tools will get you to the right ballpark quickly.

What's included in the free tier?

+

Four full tools - Biochar Calculator, Footprint Analyser, CO₂e Converter and Water Project Calculator - plus the Methodology Selector and Personal Carbon Score. All completely free, no time limit, no card required. Upgrade to Pro for feasibility modelling, cookstove, solar, borehole and forestry calculators, verification cost estimation, credit pricing, branded PDF exports, share links and embeddable tools.

Can I cancel Pro at any time?

+

Yes - cancel any time from your account. No long-term commitment. You keep Pro access until the end of your billing period.

Do you offer Enterprise pricing for teams?

+

Yes - Enterprise at £299/month adds lead-generating embeddable calculators, sales pipeline visibility, opportunity screening, branded proposals, team access and priority onboarding support. It is best introduced with a walkthrough so campaigns, proposal workflows, team access and embed requirements are aligned before rollout.

How do I know which methodology to use for my project?

+

Use the free Methodology Selector tool - pick your project type, scale, region and priority (credit quality vs volume vs speed) and it returns ranked recommendations with a plain-English explanation of why each standard suits your project. It covers cookstoves, water, biochar, solar, forestry/ARR, REDD+, agricultural land management, methane capture and blue carbon.

Can I share my calculations with colleagues or funders?

+

Yes - Pro and Enterprise users can generate a shareable link from any calculator. The link opens a clean read-only project card showing your key results and inputs, without requiring the recipient to have an account. Useful for sharing feasibility estimates with funders or project partners before a meeting.

How are emission factors kept up to date?

+

We update emission factors annually in line with UK DESNZ guidance and IPCC updates. Pro users are notified when factors change so you can rerun affected calculations.

Can I embed calculators or project displays on my own website?

+

Yes. Pro and Enterprise plans include embeddable calculators, impact counters, project maps and lead-generation widgets. You can preview them in the embed docs, then copy a live iframe into your website or client portal.

Give it a go.
It's free.

No card, no commitment. If it's useful, great. If you need more, Pro is £49/mo.

Start free Talk to us

The Carbon Workbench - Explore the guides, then move into the right tool.

Start free Explore guides