Science

Carbon Offset Calculator

Trees and cost to offset your emissions.

Enter your values

Enter the annual co2 in tonnes.

Enter the co2 per tree per year in tonnes.

Enter the offset price per tonne in $.

Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.

Results
Trees needed
428
Offset cost per year
$169.20
Cost per month
$14.10
Lifetime (40 yr) offset cost
$6,768.00

Quick answer

Offsetting a tonne of CO2 costs money or requires roughly 40 tree-years of sequestration.

Trees = tonnes CO2 ÷ tonnes per tree per year

At a glance

What it doesTrees and cost to offset your emissions.
CategoryScience
Inputs neededAnnual CO2, CO2 per tree per year, Offset price per tonne
Main outputTrees needed
FormulaTrees = tonnes CO2 ÷ tonnes per tree per year
CostFree — no sign-up, no download

How to use the Carbon Offset Calculator

  1. 1Enter your annual carbon footprint in tonnes.
  2. 2Adjust sequestration per tree if you have local data.
  3. 3Enter the offset price per tonne.

Inputs explained

Annual CO2(tonnes)
Enter the annual co2 in tonnes.
CO2 per tree per year(tonnes)
Enter the co2 per tree per year in tonnes.
Offset price per tonne($)
Enter the offset price per tonne in $.

Worked example

Using the values the calculator loads with:

Inputs

  • Annual CO29.4 tonnes
  • CO2 per tree per year0.022 tonnes
  • Offset price per tonne18 $

Results

  • Trees needed428
  • Offset cost per year$169.20
  • Cost per month$14.10
  • Lifetime (40 yr) offset cost$6,768.00

Frequently asked questions

Are offsets effective?

Quality varies hugely — verified removal credits cost far more than avoidance credits.

How much CO2 does a tree absorb?

About 22 kg a year once mature, far less when young.

What do I need to enter into the Carbon Offset Calculator?

Just 3 values: annual co2, co2 per tree per year, offset price per tonne. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.

How does the Carbon Offset Calculator work out the answer?

Offsetting a tonne of CO2 costs money or requires roughly 40 tree-years of sequestration. It applies the formula Trees = tonnes CO2 ÷ tonnes per tree per year and shows the working so you can check each step by hand.

Is the Carbon Offset Calculator free, and do I need an account?

It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.

Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.