At 5% bigger checks, extra sales are $125,000. After 30% ingredient costs on those extra sales, $87,500 remains. A 2% saving on the new $787,500 ingredient bill adds $15,750. Subtract $3,588 for ShiftLift: $99,662 remains before other added costs.
At 10% bigger checks, extra sales are $250,000. After 30% ingredient costs on those extra sales, $175,000 remains. A 5% saving on the new $825,000 ingredient bill adds $41,250. Subtract $3,588 for ShiftLift: $212,662 remains before other added costs.
Food-cost savings mean 2%–5% off the ingredient bill, not a drop of 2–5 percentage points in your food-cost rate. Return shown = the gain after ingredients and ShiftLift, divided by $3,588. Other added costs would need to be subtracted to work out your actual profit return.