Calculations

Lifespan time savings from cooking at twice the speed
4 year average lifespan x  365 days in a year x  average 1.5 hours per day savings = 2,190 hours or 91 days or 3 months

Collecting firewood
Ugandans typically spend 2-6 hours collecting firewood. Stove saves 66% fuel. Savings is 1-3 hours.

Lifespan USD savings
.97 USD saved per day x 365 days in year x 4 year lifespan = $1,416 USD

Lifespan time savings from collecting firewood
4 year lifespan  x 365 days in a year x average 2 hours saved daily =2,920 hours or 122 days or 4 months

People impacted
61,000 stoves distributed x average 6 people per household in Uganda and Sudan = 366,000 people

Tons CO2
61,000 stoves x 6 tons CO2 emissions avoided per stove per year x 4 year lifespan = 1,464,000 tons CO2 avoided

Equivalent of cars taken off road
1,464,000 tons CO2 / 4.6 tons CO2 per car per year = 318,260 cars 

Collective time savings from cooking at twice the speed
2,190 hours cooking x 61,000 = 133,590,000 hours (5,566,250 days, 185,541 months, or 15,461 years)

Collective time savings from collecting firewood
2,920 hours x 61000 = 178,120,000 hours, (7,421,666 days, 247,388 months, or 20,615 years)

Collective USD savings
$1,416 USD x 61,000 = $86 million