Reduction Value Calculation
The reduction value shows you how much CO₂eq you save with your purchase. Example calculation below.
Definitions
co2_value (g) = 2667
This is the CO₂-equivalent value associated with your product. Our example product accounts for 2667 grams.
daily_food_units = 0.32
Short for "Daily Food Unit", this is the number of Daily Food Units associated with your product. Our example product has 0.32.
global_co2_per_daily_food_unit (g) = 3894
This is the global CO₂ per Daily Food Unit ratio, that we have calculated based on the millions of products that we have analyzed.
Result
Reduction value = global_co2_per_daily_food_unit × daily_food_units - co2_value
Reduction value = 3894 × 0.32 - 2667 = -1420.92
Hence, in this example your reduction value is around -1421 g CO₂eq which means you emit more compared to the average.
- Positive values: Your product saves CO₂ compared to average consumption
- Negative values: Your product has higher emissions than average
Relationship to Improvement Percentage
It is also possible to calculate the reduction value based on the Improvement Percentage:
Improvement percentage = 1 - (co2_value / daily_food_units) / global_co2_per_daily_food_unit
Reduction value = daily_food_units × global_co2_per_daily_food_unit × improvement_percentage
Derivation
Reduction value = global_co2_per_daily_food_unit × daily_food_units - co2_value
Reduction value / daily_food_units = global_co2_per_daily_food_unit - co2_value / daily_food_units
co2_value / daily_food_units = global_co2_per_daily_food_unit - Reduction value / daily_food_units
Improvement percentage = 1 - (co2_value / daily_food_units) / global_co2_per_daily_food_unit
Improvement percentage = 1 - (global_co2_per_daily_food_unit - Reduction value / daily_food_units) / global_co2_per_daily_food_unit
1 - Improvement percentage = (global_co2_per_daily_food_unit - Reduction value / daily_food_units) / global_co2_per_daily_food_unit
(1 - Improvement percentage) × global_co2_per_daily_food_unit = global_co2_per_daily_food_unit - Reduction value / daily_food_units
global_co2_per_daily_food_unit - (1 - Improvement percentage) × global_co2_per_daily_food_unit = Reduction value / daily_food_units
global_co2_per_daily_food_unit × (1 - (1 - Improvement percentage)) = Reduction value / daily_food_units
daily_food_units × global_co2_per_daily_food_unit × Improvement percentage = Reduction value
Related Concepts
- Daily Food Unit - Normalizes food amounts for comparison
- Improvement Percentage - Relative comparison to average
- Climate Score - What qualifies as climate-friendly