Batch Yield Formula: Theoretical, Actual and Reconciled

Batch yield is what a batch actually made against what it should have made: yield = actual good units ÷ theoretical units × 100. The theoretical figure comes from the inputs: their total weight, less the loss you expect in cooking or processing, divided by the weight of one unit. Reconciliation goes one step further and accounts for every unit the batch should have made, good, rejected, sampled or unaccounted, so a low yield has a reason instead of a shrug. In the example below, a batch of lilikoi butter should make 63 jars and makes 58 good ones, a yield of 92.1%, below the 95% the kitchen accepts; two jars were rejected, one was tasted, and two can't be accounted for. The shortfall adds 28 cents to every good jar's cost. Below is the formula, the example, reconciliation, limits, what yield costs, and a free calculator.

The short version

• Theoretical units = inputs × (1 − expected loss) ÷ weight of one unit.
• Yield = good units ÷ theoretical units.
• Reconcile: good + rejected + samples + unaccounted = theoretical; investigate the unaccounted.
• Set a lowest yield you accept per product, and look at every batch below it.
• A low yield raises the cost of every good unit, because the same ingredients made fewer.
• Track yield batch by batch; a recipe's yield drifts without anyone deciding it should.
• TaroStack records what each batch made against its recipe and costs it on what came out good. More below.

The formula

The expected loss is what you know happens: water cooked off, skins and trim, product left in the kettle. Measure it over several batches and write it into the recipe; guessing it makes every yield figure wrong.

A worked example

Windward Roots, the made-up taro business I use in these examples, makes lilikoi butter in 8 oz jars, 227 g each:

With a 10% loss in cooking, 16.1 kg makes 14.49 kg of lilikoi butter, which fills 63 jars of 227 g. The batch made 58 good jars.

Reconciliation: where the other five went

Reconciliation turns "it came out short" into a list. The two rejects and the tasting jar are known. The two unaccounted jars, about 450 g of product, are the part to investigate: left in the kettle, spilled at the filler, or a recipe whose cooking loss is 13%, not 10%. If the same gap shows up batch after batch, it's the recipe, not the day. How a nonconformance like the underfilled jars is recorded is in nonconforming product form.

What a low yield costs

The batch costs $202.99: $85.04 of ingredients, $60 of labor and $57.95 for the 61 jars and labels used. Divided by the theoretical 63 jars it would be $3.22 a jar; divided by the 58 good ones it's $3.50. The shortfall adds 28 cents to every good jar, $16.24 on this one batch, and the same again on every batch with the same problem. That's the yield variance: the cost of making fewer good units than the recipe promised from the same inputs. How actual and standard costs compare line by line is in batch costing example, and the month's view across every batch is in production KPIs.

Setting a yield limit

Set the lowest yield you'll accept for each product from its own history: the average of the last ten batches, less a little. A batch below it gets a look before the next one is made, while the cause is still in the room. A product whose yield keeps drifting down needs its recipe's loss figure or its process checked. A yield above 100% is a warning too: the inputs weren't what the record says, or the jars are underfilled.

Get the calculator

Download the batch yield calculator. Type the batch's inputs with their prices, the expected loss, the unit size, packaging, labor and your yield limit, then the good, rejected and sampled units; it works out the theoretical units, the yield, the reconciliation, the status against your limit, and what the shortfall cost. It's an ordinary Excel file with no macros, and it works in Google Sheets, LibreOffice and Numbers.

Where this stops working

The calculator works for the batch you type in. The kitchen makes forty batches a month of a dozen products, and the yield is worked out, if at all, at the end of the month from batch sheets. By then the lilikoi butter has come out short eight times, and nobody knows whether the cooking loss is 13% or the filler is spilling, because each batch was looked at alone, weeks later.

How TaroStack does it

TaroStack records each batch against its recipe as it's made, so yield is a fact of the batch, not a sum at month end.

Every batch against its recipe. Each product is a recipe with a scrap %, so the expected loss is part of the recipe. Recording a batch takes the inputs off stock from the lots used, records what came out good, and costs the batch on the good units, at what you paid for each lot, so a short batch's higher cost per jar is visible when it's made.

Recipe truth. From your own batch history, recipe truth shows whether a recipe yields what it claims and which ingredient's quantity is wrong, so a cooking loss of 13% instead of 10% shows up as a pattern, not a feeling. Each batch shows its actual cost against the recipe's standard cost.

And the rejects, accounted for. Batch record forms carry your own fields, like fill weight, with limits, so an underfilled jar is flagged when it's checked. Rejected and tasted units come off stock as adjustments with their reason, damaged or sample, so losses are reported by reason, item and site.

Recipes with scrap %, batches, actual against standard cost and recipe truth are on every plan, from $49 a month. The first 30 days are free, with no credit card. If you'd like a hand setting up, ask, and we'll do it with you.

Questions people also ask

How do you calculate batch yield?

Divide the good units the batch made by the theoretical units it should have made, and multiply by 100. In the example, 58 ÷ 63 = 92.1%.

What is theoretical yield in a batch?

What the inputs should make: their total weight, less the expected loss in cooking or processing, divided by the weight of one unit. In the example, 16.1 kg less 10% fills 63 jars of 227 g.

What is batch yield reconciliation?

Accounting for every unit the batch should have made: good, rejected, sampled and unaccounted. The unaccounted units are the ones to investigate.

What is yield variance?

The cost of making fewer good units than the recipe promised from the same inputs. In the example, the shortfall adds 28 cents to each good jar, $16.24 on the batch.