Recipe changes

How to Recalculate Recipe Cost After an Ingredient Price Change

Trace an ingredient price change through line cost, revised recipe cost, batch impact, and per-serving impact without changing the recipe basis.

When an ingredient price changes, the cleanest update isolates the affected line before changing the whole recipe total. A substitution compares the old and replacement line costs; a price-change review compares old and new unit prices at a fixed quantity and yield. This guide shows how to calculate the signed difference, update the batch, and report the per-serving effect while keeping the original recipe and yield basis intact.

How to isolate and roll forward a price change

Identify the affected basis. Confirm the old and new prices use the same unit and valuation basis. If both are matching usable prices, enter the recipe quantity directly; if they are AP prices and the recipe quantity is EP, use the fixed measured yield branch.
Calculate the line change first. Use T31 for a known old line cost and replacement line cost, or T33 when the change is expressed as old and new unit prices multiplied by a fixed recipe quantity.
Recalculate the batch once. Use T32 to remove the old line and add the new line. The current recipe cost must contain the old line exactly once.
Report the per-serving effect. In T33, enter the current batch cost and equivalent servings when you need the revised batch and per-serving cost. Keep the batch serving basis unchanged.
Review the non-price assumptions. A price update does not prove that a substitute is culinarily equivalent, that yield stayed constant, or that other recipe lines remained unchanged. Record those assumptions separately.

Trace a price change from line to serving

Compare Old and new price
Same unit and valuation basis for both prices.
Adjust Affected line delta
Replacement line cost − original line cost, with yield applied only in AP/EP mode.
Roll up Revised batch
Current batch − old line + new line, or current batch + delta.
Allocate Per-serving impact
Batch delta ÷ unchanged equivalent servings.

Hold the recipe quantity and measured yield fixed, isolate the affected line, then carry the signed difference into the batch and per-serving totals.

Choose the price-change path

T31, T32, and T33 describe related but distinct inputs. Use the path that matches the evidence in the costing record.

Ingredient price-change decisions
Known record	Calculator	Equation	Key condition
Old and replacement line costs	Substitution cost delta	New line cost − old line cost	Both line costs are already valued at the same recipe quantity.
Current batch, old line, and new line	Substitution what-if recipe	Current batch − old line + new line	Current batch includes the old line exactly once.
Old/new unit prices and matching quantity	Price-change impact, matching basis	(New price − old price) × recipe quantity	Prices and quantity share the same basis.
AP prices and EP recipe quantity	Price-change impact, AP basis	(New − old) × EP quantity ÷ yield fraction	Use one fixed measured yield; do not apply loss twice.

Separate a substitution from a price-only change

T31 and T32 assume the old and replacement ingredient lines are already costed at the defined recipe quantity. T33 starts from old and new unit prices and applies a fixed quantity and, when required, a fixed measured yield. Keeping these inputs distinct prevents a known line-cost replacement from being mixed with an AP/EP price calculation.

Worked example: fixed-yield AP price increase

An ingredient price rises from $3.00 to $3.50 per AP unit. The recipe uses 4 usable units, the fixed measured yield is 80%, the current batch cost is $30.00, and the batch produces 10 equivalent servings. The same recipe has an old ingredient line of $2.00 replaced by a $2.75 line.

Inputs

Old AP price: $3.00 per AP unit
New AP price: $3.50 per AP unit
Recipe quantity: 4 usable EP units
Fixed yield: 80 %
Current batch: $30.00 for 10 servings
Substitution line example: $2.00 → $2.75

AP-to-EP costed quantity = 4 usable units ÷ 0.80 = 5 AP units.
Old line = $3.00 × 5 = $15.00; new line = $3.50 × 5 = $17.50; line delta = $2.50.
Revised batch = $30.00 + $2.50 = $32.50; per-serving change = $2.50 ÷ 10 = $0.25, so revised cost per serving is $3.25.
Separate substitution check: $2.75 − $2.00 = $0.75, and $12.00 − $2.00 + $2.75 = $12.75.

AP quantity: 4 ÷ 0.80 = 5 AP units
Line delta: ($3.50 − $3.00) × 5 = $2.50
Per-serving impact: $2.50 ÷ 10 = $0.25/serving
Substitution delta: $2.75 − $2.00 = $0.75

Result: $2.50 batch increase; $0.25 per serving; $3.25 revised serving cost

Keep the price difference, yield division, batch delta, and per-serving division unrounded until display. T31, T32, and T33 display dollar results to cents; AP/EP mode requires the measured yield and applies it once.

Use the same quantity and valuation basis at both prices

Matching-basis mode is appropriate when old and new prices are already expressed on the same usable or purchase basis as the recipe quantity. AP/EP mode is for AP prices paired with a usable EP recipe quantity and a measured yield. The calculator applies the yield fraction only in that AP/EP branch.

Price and quantity basis checks
Basis	Price input	Recipe quantity input	Yield treatment
Matching	Old and new prices share the quantity basis	Quantity matches the price unit	Use a factor of 1; do not add a yield.
AP/EP	Old and new prices are AP prices	Quantity is usable EP quantity	Divide by the fixed measured yield fraction once.
Substitution line	Old and new line costs are already calculated	Both lines use the same recipe quantity	Compare line totals directly.
Invalid mixture	One price is AP and the other is EP	Or yield is changed between prices	Normalize the record before calculating.

Carry the delta into batch and serving totals

For a batch update, remove the old line and add the new line. For a price-only impact, add the signed delta to the current batch when the current batch contains the old line. Divide that delta by the unchanged equivalent serving count to report the per-serving effect; do not change the denominator simply because price changed.

Recheck the revised totals

The example starts at $30.00 for 10 servings. Adding the $2.50 delta gives $32.50, and $32.50 ÷ 10 = $3.25 per serving. The serving count stays fixed so the effect remains attributable to the price change.

Price-change formula reference

Use comparable prices and quantities. In AP/EP mode, hold the measured yield fixed; in matching mode, do not reapply a yield.

Recipe change equations
Task	Equation	Condition
Substitution delta	Replacement line cost − original line cost	Both lines are costed at the same recipe quantity.
Revised recipe cost	Current recipe cost − original line cost + replacement line cost	Current total includes the original line once.
Matching-basis price impact	(new unit price − old unit price) × recipe quantity	Prices and quantity use the same basis.
AP/EP price impact	(new AP price − old AP price) × EP quantity ÷ yield fraction	Yield is measured, fixed, and applied once.
Per-serving impact	Batch delta ÷ unchanged servings	Serving basis remains comparable.

Keep the old basis with the revised recipe

Record the old and new prices, price basis, quantity, measured yield, affected line, current batch total, serving count, and effective date. Preserve the prior recipe cost so a later review can distinguish a supplier change from a recipe or yield change.

Update the affected line before the whole recipe

A traceable price update keeps the recipe quantity, yield, serving count, and unaffected lines fixed while isolating the changed ingredient. Calculate the signed line delta, roll it into the batch once, and divide the delta by the unchanged serving basis when needed. The calculators describe arithmetic impact; they do not decide whether a replacement performs the same in production or whether the menu price should change.