Performance Management · Material mix and yield variances

Material Mix and Yield Variances Explained for ACCA PM

Updated 11 October 2026 · Fact-checked

Material mix and yield variances split the total material usage variance when a product uses several substitutable inputs. The mix variance shows the cost effect of using a different blend of inputs from standard. The yield variance shows the effect of getting more or less output from the total input used. Together they equal the usage variance.

Understand Material Mix and Yield Variances Basics

A simple usage variance compares the quantity of each material used with the standard quantity for the actual output, priced at standard cost. It tells you that you used too much or too little. It does not tell you why.

When a product is made from two or more inputs that can be swapped for each other, there are two possible reasons. Management may have changed the blend of inputs, for example more of the cheap input and less of the dear one. Or the process may have turned the total input into more or less output than expected, because of waste, loss or poor quality. These have different causes and different owners, so we separate them.

The mix variance isolates the blend effect. It asks: if the actual total input had been used in the standard proportions, what would it have cost, compared with the actual blend, both at standard prices? The yield variance isolates the output effect. It asks: how much more or less total input was used than the standard allows for the actual output, valued at the standard average cost per unit of input?

The analysis only makes sense when inputs are genuinely substitutable and the mix is something management can control, such as chemicals, blended foods, metals or fertilisers. If the proportions are fixed by the recipe or the technology, a mix variance has no meaning, and you report only the usage variance.

A typical result: a cheaper blend gives a favourable mix variance, but the lower quality causes more loss and an adverse yield variance. Whether this is a good trade depends on whether the saving is bigger than the loss. Always remember that mix plus yield equals total usage.

Key rules to remember

Total material usage variance: Σ (standard quantity for actual output − actual quantity used) × standard price per unit; Work out each material separately and add. Positive is favourable, negative is adverse.
Material mix variance: Σ (actual total input in standard mix − actual quantity of each input) × standard price per unit; Actual total input is the sum of all inputs actually used. Share it in the standard proportions.
Material yield variance: (standard total input for actual output − actual total input) × standard average cost per unit of input; Standard average cost per unit of input = standard cost of one batch of inputs ÷ total input units in the batch.
Reconciliation: Mix variance + yield variance = total material usage variance; Use this to check your work. Use it also as a shortcut to find one variance from the other two.
Standard input for actual output: Actual output × (standard input in batch ÷ standard output in batch); This gives the total input the standard allows for the actual output.

How to solve Material Mix and Yield Variances Basics questions

Use this method for any mix and yield question. Keep the work in a small table so that you can check it.

1Write down the standard for one batch: each input, its quantity and its standard price, plus the total input, the total standard cost and the standard output.
2Work out the standard average cost per unit of input: total standard cost of the batch ÷ total input units.
3Calculate the standard quantity of each input for the actual output. Scale the batch up using actual output ÷ standard output.
4Calculate the usage variance for each material: (standard quantity − actual quantity) × standard price. Add them.
5Add up the actual quantities to get actual total input. Share it in the standard proportions to get the actual input in standard mix.
6Calculate the mix variance for each material: (actual in standard mix − actual quantity) × standard price. Add them.
7Calculate the yield variance: (standard total input for actual output − actual total input) × standard average cost per unit.
8Check that mix + yield = usage. Label each variance F or A and comment on what it means.

Quickest way: Yield first, then mix by difference

When to use it: Use this when time is short and you only need the totals, not the variance for each material.

Find the standard total input for the actual output and compare it with actual total input. Multiply the difference by the standard average cost per unit of input. This is the yield variance.
Calculate the total usage variance by summing (standard quantity − actual quantity) × standard price for each material.
Mix variance = usage variance − yield variance, keeping the signs.
Do a quick sense check: if the actual mix used more of the dearer input than standard, the mix variance should be adverse.

Common mistakes in Material Mix and Yield Variances Basics

Using actual prices instead of standard prices in mix and yield variances.
Students mix these up with the price variance, which does use actual prices.
Fix: Mix, yield and usage variances are quantity variances. Always value them at standard price.
Calculating the yield variance using the standard price of one material instead of the average standard cost per unit of input.
The yield variance is about total input, and students forget it has to be valued as a blend.
Fix: Divide the standard cost of one batch by the total input units in the batch. Use that figure.
Sharing actual total input in the wrong proportions, or sharing standard input for actual output instead.
Two totals appear in the question, and the wrong one gets picked up.
Fix: For the mix variance, take the actual total input and share it in the standard ratio. Then compare with what was actually used.
Getting the sign wrong.
The order of subtraction changes between textbooks and notes.
Fix: Always do standard (or standard-mix) minus actual. A positive answer is favourable and a negative one is adverse.
Finding that mix + yield does not equal usage and moving on.
Time pressure, or the belief that small errors do not matter.
Fix: They must always agree. If they do not, recheck the standard quantities and the average cost per unit before going further.
Applying mix variances where the inputs cannot be substituted.
Students apply the formula to any multi-input process.
Fix: Check that management can vary the proportions. If not, report only the usage variance and say why.

Worked examples

Example 1

A product has the following standard for one batch: Material A 60 kg at $10 per kg and Material B 40 kg at $20 per kg. Total input is 100 kg and standard output is 90 kg. In a period, actual output was 4,500 kg. Actual input was 3,200 kg of A and 1,900 kg of B. Calculate the total usage, mix and yield variances.

Show the solution

Standard cost of one batch = (60 × 10) + (40 × 20) = 600 + 800 = $1,400. Standard average cost per kg of input = 1,400 ÷ 100 = $14.
Standard input for actual output = 4,500 × (100 ÷ 90) = 5,000 kg. Split 60:40 this is A 3,000 kg and B 2,000 kg.
Usage variance A = (3,000 − 3,200) × 10 = $2,000 adverse. Usage variance B = (2,000 − 1,900) × 20 = $2,000 favourable. Total usage variance = $0.
Actual total input = 3,200 + 1,900 = 5,100 kg. In standard mix: A = 5,100 × 60% = 3,060 kg and B = 5,100 × 40% = 2,040 kg.
Mix variance A = (3,060 − 3,200) × 10 = $1,400 adverse. Mix variance B = (2,040 − 1,900) × 20 = $2,800 favourable. Total mix variance = $1,400 favourable.
Yield variance = (5,000 − 5,100) × 14 = $1,400 adverse.
Check: 1,400 F + 1,400 A = 0, which equals the usage variance.

Answer: Usage variance $0; mix variance $1,400 favourable; yield variance $1,400 adverse. More of the cheaper material A was used than standard, but total input was 100 kg higher than the standard allows for the output.

Example 2

A liquid is made from Chemical X (30 litres at $4 per litre) and Chemical Y (20 litres at $9 per litre) per batch. Standard output per batch is 45 litres. Actual output was 2,250 litres from 1,400 litres of X and 1,200 litres of Y. Calculate the usage, mix and yield variances, using the quick method for the mix variance, and comment briefly.

Show the solution

Standard cost of one batch = (30 × 4) + (20 × 9) = 120 + 180 = $300. Standard average cost per litre of input = 300 ÷ 50 = $6.
Standard input for actual output = 2,250 × (50 ÷ 45) = 2,500 litres. In the 30:20 ratio this is X 1,500 litres and Y 1,000 litres.
Usage variance X = (1,500 − 1,400) × 4 = $400 favourable. Usage variance Y = (1,000 − 1,200) × 9 = $1,800 adverse. Total usage variance = $1,400 adverse.
Actual total input = 1,400 + 1,200 = 2,600 litres. Yield variance = (2,500 − 2,600) × 6 = $600 adverse.
Mix variance = usage − yield = 1,400 A − 600 A = $800 adverse.
Check by full method: actual input in standard mix is X 1,560 and Y 1,040. Mix X = (1,560 − 1,400) × 4 = $640 F. Mix Y = (1,040 − 1,200) × 9 = $1,440 A. Net = $800 A. This agrees.
Comment: more of the dearer Y was used than standard, and total input was higher than the standard allows. Both point to a problem in the process, so investigate the cause of the loss and the change of blend.

Answer: Usage variance $1,400 adverse; mix variance $800 adverse; yield variance $600 adverse. Both the blend and the output were worse than standard.

Exam tips

In objective test cases, mix and yield questions are often short. Write the standard batch and the average cost per unit on your rough paper first, so you can reuse them for every question in the case.
Check the output is stated in the same units as the standard. If the standard shows a loss, you must use the standard output, not the total input, to scale up.
In a written question, show a clear table with standard quantity, actual quantity, and actual in standard mix. Marks are given for method even if one figure is wrong.
Always add a short comment. Say what the variance shows and whether the two variances offset each other, for example a cheaper blend that causes more waste.
Remember that mix + yield = usage. Use it as a fast check before you move on.

Practice questions from Material mix and yield variances

Material Mix and Yield Variances Basics in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Material Mix and Yield Variances Basics: frequently asked questions

Why do we split the material usage variance into mix and yield?

Because the total hides two different causes. One is a change in the blend of inputs, and the other is the amount of output obtained from the total input. Splitting them lets management see who is responsible and what to correct.

What is the difference between material usage variance and yield variance?

The usage variance compares the quantity of each material used with standard for the actual output. The yield variance only looks at total input against the standard total input for the actual output, at the standard average cost. The usage variance is the sum of the yield and mix variances.

When can I use mix and yield variances?

Use them when the inputs are substitutable and management can change the proportions, such as in blending or chemical processes. If the proportions are fixed by the product design, the mix variance is not meaningful and only usage is reported.

Is a favourable mix variance always good news?

No. A cheaper blend may reduce quality and cause more waste, which shows up as an adverse yield variance. You must compare the two variances before judging the decision.