Q factor
Also called: quotient factor
The Q factor is a fixed allowance added to every plate cost to cover items too small or too shared to cost individually — cooking oil, butter, seasoning, condiments, complimentary bread. Most kitchens set it at 2–5% of plate cost or a flat $0.25–$0.75 per cover.
Sizing it from real data
Q factor per cover = Monthly spend on uncosted items ÷ Monthly covers
This is the honest way to set it. The guess is where people go wrong in both directions.
Worked example · A 1,900-cover month
- Cooking oil
- $410
- Butter (non-recipe)
- $285
- Salt, pepper, dry seasoning
- $140
- Condiments + ramekins of sauce
- $220
- Bread service
- $560
- Total uncosted
- $1,615
- Covers
- 1,900
- Q factor per cover
- $0.85
Higher than the usual rule of thumb — driven entirely by the bread service. That's the point of measuring rather than assuming.
Two refinements worth making: apply a different Q factor to dishes that genuinely differ (a $6 side does not consume the bread service), and re-derive it annually. A Q factor set once in 2023 is understating a 2026 plate.
Run the numbers
Recipe cost calculator
The guide that works it through
Recipe Costing, Step by Step
How to cost a recipe properly: yield-adjusted ingredient costs, sub-recipes, the Q factor, and a full worked example from invoice to plate cost to menu price.