Net Zero Calculator Formula
Understand the math behind the net zero calculator. Each variable explained with a worked example.
Formulas Used
Residual Emissions at Target
residual_emissions = residualTotal Reduction Achieved
reduction_achieved = total_reducedAnnual Offsets Needed
offset_needed = residualAnnual Offset Cost
offset_cost = residual * offset_priceVariables
| Variable | Description | Default |
|---|---|---|
current_emissions | Current Annual Emissions(metric tons CO2e) | 1000 |
reduction_pct | Annual Reduction Rate(%) | 7 |
target_year | Years to Net Zero(years) | 10 |
offset_price | Offset Price per Ton(USD) | 30 |
residual | Derived value= current_emissions * pow(1 - reduction_pct / 100, target_year) | calculated |
total_reduced | Derived value= current_emissions - residual | calculated |
How It Works
How to Plan for Net Zero
Net zero means reducing emissions as much as possible and offsetting the remainder.
Formula
Residual Emissions = Current * (1 - Annual Reduction %)^Years
Offsets Needed = Residual Emissions
The Science Based Targets initiative requires at least 90% absolute reduction before relying on offsets for net zero. Remaining emissions must be neutralized through high-quality carbon removal.
Worked Example
A company emitting 1,000 tons CO2e reduces 7% annually over 10 years with $30/ton offsets.
current_emissions = 1000reduction_pct = 7target_year = 10offset_price = 30
- 01Residual: 1,000 * (1 - 0.07)^10 = 1,000 * 0.484 = 484 metric tons
- 02Total reduced: 1,000 - 484 = 516 metric tons
- 03Offsets needed: 484 metric tons/year
- 04Offset cost: 484 * $30 = $14,520/year
Ready to run the numbers?
Open Net Zero Calculator