How we calculate

An audit lasts 7 days. Each day, your team weighs the food thrown away, by shift and by waste category: pre-consumer waste (spoilage, trimming, overproduction and other kitchen waste) and post-consumer waste (plate waste, buffet returns). Guests are counted for the same days, so waste can be compared per guest between a quiet week and a busy one.

Nothing is estimated or scaled up. A week that is only partly entered is calculated on the days entered so far, and every figure says how much of the period it covers.

The kilograms wasted are valued at the average cost per kilogram of food you enter in the monthly data. When that is not entered, a standard estimate is used and the page says so: CA$7 per kg (US$5, €4.5 or £3.8 for audits in those currencies).

Savings are the money value of the waste avoided against a baseline: the previous audit of the same area (or location), the nearest earlier month with audit data, or the first audit week for the running total. A worse week adds nothing; it never erases a better one. With no baseline, no saving is shown.

The CO₂e, water and land figures describe the food behind a month: what you bought, not only what you threw away. They are calculated only once that month’s food cost has been entered; without it, the app asks for monthly data instead of showing a figure.

Kilograms purchased = monthly food cost ÷ average cost per kilogram. Each kilogram is weighted by your purchase mix across eight food categories (a mix that does not add up to 100% is read as proportions), using these factors per kilogram purchased:

Where the waste goes adds (or, for a diversion, subtracts) emissions per kilogram of waste. The headline CO₂e never goes below zero, but the parts are always shown with their true values:

The share of each pre-consumer waste category treated as avoidable, to show how much of the footprint could have been prevented (reported beside the total, never added to it):

Factors: the BetterTable Carbon Footprint of Food model (version env-v2, 2026). These are estimates for management and reporting, not a certified life-cycle assessment or a verified carbon inventory.

The app shows the 17 goals and lights one only where your own audit and monthly data back it: up to 13 can be measured this way. SDGs 9, 10, 16, 17 are BetterTable programme badges, shown separately and never counted as measured.

A report’s SDG section lists a goal only when the data for it exists:

• SDG 2, Zero Hunger: surplus meals donated, only when donations were recorded
• SDG 6, Clean Water and Sanitation: the water footprint of the food, plus site water use when entered
• SDG 12, Responsible Consumption and Production: food waste measured for the period, and waste per guest (target 12.3)
• SDG 13, Climate Action: the CO₂e footprint of the food behind the period
• SDG 15, Life on Land: the land footprint of that food

• No promised reduction: results depend on what each kitchen changes. A result we quote names the business, the weeks compared and how it was measured.
• No carbon neutrality, offsets or "Net Zero" certification.
• An SDG shown as met is backed by the business’s own figures, not by membership alone.
• Global context: around a third of the food produced worldwide, some 1.3 billion tonnes a year, is lost or wasted across the whole supply chain (FAO, 2011). That figure is not about foodservice alone.