Can I Use an Online Calculator to Estimate CSRD Emissions?

When small and medium-sized enterprises (SMEs) first face sustainability reporting, one of the biggest worries is: how do we actually calculate our emissions?

The good news: yes, you can use online calculators to estimate your emissions for Corporate Sustainability Reporting Directive (CSRD)-style disclosures or the Voluntary Sustainability Reporting Standard for SMEs (VSME).

But not all tools are equal. Let’s explore your options.

Option 1: Free Online Calculators

Many government agencies, NGOs, and climate initiatives provide free calculators that can convert your energy use into emissions.

Examples:

• SME Climate Hub Carbon Calculator — Designed specifically for small businesses, covering fuel, electricity, and travel.
• Carbon Trust SME Carbon Footprint Calculator — A UK-based tool for SMEs to estimate Scope 1 and Scope 2 emissions.
• CoolClimate Business Calculator — Developed by UC Berkeley, aimed at small businesses globally.

Pros:

• Quick and easy for one-off estimates.
• Good for first-time users who want to “test the waters.”

Cons:

• Often use generic emission factors, not always tailored to your country.
• Don’t store your data — you’ll need to start again each year.
• Export formats may not align with what banks or clients ask for.

These are useful if you just want a rough idea, but less helpful if you need to report regularly. For more detailed guidance, see our step-by-step guide to reporting Scope 1 and 2 emissions.

Option 2: Spreadsheet Templates (Excel, Airtable)

You can also download templates or build your own in Excel.

Pros:

• Flexible and customisable to your business.
• Easy to share internally.

Cons:

• Requires manual data entry and formula management.
• Risk of errors or inconsistent methods.
• Takes time each year to update.

This approach works if you already use spreadsheets heavily — but it’s easy to get bogged down.

Option 3: Professional ESG Software

There are enterprise-level ESG platforms aimed at large companies.

Pros:

• Robust, with full CSRD/ESRS compliance.
• Advanced features like target-setting and scenario modelling.

Cons:

• Expensive and complex for SMEs.
• Often require consultancy support to implement.

For most SMEs, this level of detail is more than they need.

The SME-Friendly Alternative: Terrara

If you want something in between — simple but reliable — this is where Terrara comes in.

With Terrara:

• You enter your bills and fuel data once, and the tool applies the right factors automatically.
• Your data is stored, so you can track progress over time.
• You can see ongoing metrics at a glance — not just once a year.
• When needed, you can generate clear, professional reports in the VSME/CSRD format that banks or clients will expect.

Think of it as moving beyond “basic calculators” into a system designed for SMEs: quick to use, low effort, but giving you confidence that your numbers are right.

Bottom Line

Yes, you can absolutely use free online calculators or a spreadsheet to estimate emissions for CSRD reporting. But if you want to:

• Save time,
• Avoid manual errors, and
• Present your results in a professional way,

then a tool like Terrara makes reporting easier — and lets you focus on running your business, not wrestling with spreadsheets.

Key Terms

• Corporate Sustainability Reporting Directive (CSRD) — An EU law that requires large companies — and eventually some medium-sized ones — to report on their environmental and social impacts. Smaller suppliers are not directly in scope but may be asked for CSRD-style data by banks or bigger clients.
• Voluntary Sustainability Reporting Standard for SMEs (VSME) — A simplified framework designed to help SMEs share sustainability information. It is voluntary but can help SMEs respond to client or bank requests.
• Scope 1 emissions — Direct greenhouse gas emissions from sources a company owns or controls, such as fuel burned in vehicles or gas boilers.
• Scope 2 emissions — Indirect greenhouse gas emissions from purchased energy, such as electricity, heating, or cooling.
• Emission factor — A standard value that shows how much CO₂ equivalent is released per unit of energy or fuel.

✅ Free calculators are fine for a quick start. Spreadsheets work if you have time. Big ESG software is overkill for SMEs. But with Terrara, you get the ease of a calculator, the reliability of a structured tool, and the benefit of ongoing reporting — all in one place.