How to Calculate Manufacturing Cost per Unit

Manufacturing cost per unit is the factory cost of one piece you can sell or put into finished-goods stock. Add three lines for the batch — direct materials, direct labour, and manufacturing overheads — then divide by the number of saleable units.

Manufacturing cost per unit = (direct materials + direct labour + manufacturing overheads) ÷ saleable units

You can enter the same three lines on the production cost calculator. The rest of this page is the method behind that sum, with a full example in rupees. The numbers are an example. They are not a real factory's books.

What goes into each line

Prime cost is the first two lines only: direct materials plus direct labour. Manufacturing cost is prime cost plus manufacturing overheads. Cost per unit uses the full manufacturing cost. A sheet that stops at prime cost will understate the rack, the bottle, or the garment.

Direct materials

Cost each material as quantity issued × rate.

Use one unit throughout. If the store issues metres, the rate has to be per metre, not per kilogram, unless you convert on purpose and write the conversion down.

Use the rate before GST when the GST on that purchase invoice is input tax credit you can claim. The credit is not a cost. Add the GST into the material rate when you cannot claim it — for example a purchase on which credit is blocked, or a bill with no credit. Mixing the two, some lines with GST and some without, is how two people in the same factory arrive at two costs for the same job.

Scrap you sell, or offcuts you put back into stock, reduces the material cost. Scrap that is thrown away does not. Write the scrap weight and the rate next to the material total so the reduction is visible.

Direct labour

Use the wages of the people on that batch for the days or hours they spent on it. A daily-wage welder on this job for six days is direct labour. The supervisor who walks all the jobs is overhead.

Include the wage you actually pay for those days. If you also book a fixed share of ESI or PF on those wages, keep that share in the same line and use it every batch. Switching it on for one quotation and off for the next makes the costs impossible to compare.

Manufacturing overheads

These are real factory costs. They do not sit on one job card, so they have to be spread.

A practical way for a small factory:

1. List one month of factory overheads. Shed rent, production power, supervisor wages, maintenance, and shared consumables.
2. Pick a base you already measure. Machine hours if the work is on machines. Labour hours if it is mostly hand work.
3. Overhead rate = monthly factory overheads ÷ total hours in that month.
4. This batch = overhead rate × hours this batch used.

Use the same base every month. If power tariff or rent changes, rebuild the rate. A rate copied from last year will not match this year's bill.

Saleable units

Saleable units are the pieces you can invoice or move to finished goods. Units you scrapped, or rejected and could not rework, stay out of the divisor.

The money already spent on those rejected pieces stays in the batch total. That is why the good pieces cost more than a clean division by the quantity you started. Dividing by the start quantity hides the loss.

Rework that saves a piece is extra labour and sometimes extra material. Add that cost to the batch, and count the saved piece as saleable. A piece you reworked and still rejected is not saleable.

Worked example: 50 storage racks

This is an illustrative batch for a small fabrication unit making mild-steel storage racks. Every rate below is there so the arithmetic can be checked. It is not a wage survey, a quotation, or a customer's result.

The plan is 50 racks. Two fail final inspection and are cut up. Scrap from offcuts and those two racks is 35 kg. Saleable racks: 48.

Direct materials

The rates are before GST, on the assumption that input tax credit is available on these bills. If a bill had no credit, that GST would be added to the line.

Direct labour

Manufacturing overheads

Factory overheads for the month in this example:

The shed runs 800 machine hours in the month. This batch uses 80, which is one tenth.

Overhead rate = ₹59,000 ÷ 800 hours = ₹73.75 per machine hour.

This batch = 80 × ₹73.75 = ₹5,900.

Cost per saleable rack

₹1,06,720 ÷ 48 = ₹2,223.333…, which is ₹2,223.33 to the nearest paisa.

If the same batch total is divided by 50, the racks you started, the sheet shows ₹2,134.40. That is about ₹89 less on every rack you can sell. The two rejected racks did not become free. Their cost is sitting inside the 48.

Common mistakes

Dividing by the quantity started. The divisor is saleable units. Rejection stays in the batch total.

Stopping at materials, or at prime cost. Labour and factory overheads are part of manufacturing cost. A material-only number is a purchase total, not a unit cost.

Putting the office into the factory. Commission, outward freight, the city sales office, and the owner's personal drawings are not manufacturing overheads. They matter for the selling price. They do not belong in this formula.

Leaving last year's overhead rate in the sheet. Rent, power, and wages move. Rebuild the monthly rate when the bills change.

Mixing GST in and out of the material rate. Creditable GST stays out of the cost. GST you cannot claim stays in. One rule, every line.

Forgetting scrap, or deducting it twice. Subtract the scrap you sell or return to stock, once. Do not also drop the rejected pieces out of the batch total and out of the divisor. The rejected pieces leave the divisor only.

Costing a rework as zero. If someone spent another day saving a piece, that day is labour. If the piece was still scrapped, it is not a saleable unit.

Using a competitor's price as your cost. Their price is their price. Your cost is your material issue, your wages, and your shed.

What to keep with the batch

A cost you can explain six months later has four attachments:

• the material issue, with quantity, rate, and scrap
• the labour days or hours, by person
• the overhead rate for that month, and the hours you applied
• the count of saleable units, and what happened to the rejects

A bill of materials tells you the quantity that should have been issued. The issue slip tells you what left the store. When those two differ, the unit cost should follow the issue, and the difference should be visible. Work-in-progress valuation uses the same three inputs while the batch is still open. Rejection and rework is what changes the saleable count.

On a live order, the same lines belong on the production record, not in a separate notebook that accounts never sees. Factory OS is ₹2,999/month for that record. The free trial starts from the production cost calculator.

Related guides

• Production cost calculator — enter materials, labour, and overhead for a batch
• What a bill of materials is
• How to track WIP in a small factory
• Production order versus work order
• Rejection and rework

Frequently asked questions

How do I calculate manufacturing cost per unit?

Add direct materials, direct labour, and manufacturing overheads for the batch. Subtract scrap you sell or reuse. Divide by saleable units: the pieces you can sell or stock as finished goods after rejection.

What should I include in direct materials?

Raw material, bought-out parts, and packing that stays with the product, at the quantity issued to the batch. Use the pre-tax rate when you can claim GST input tax credit. Add the GST when you cannot. Reduce the total by scrap you recover.

What counts as manufacturing overhead for a small factory?

Shed rent, production power, a supervisor who covers many jobs, and machine maintenance. Spread them on machine hours or labour hours, and keep the same base each month. Sales commission, city-office rent, and the owner's drawings sit outside this cost.

Do I divide by the units I started or the units I can sell?

Divide by saleable units. The cost of rejected pieces stays in the batch, so each good piece carries a share of that loss.

Is manufacturing cost per unit the same as my selling price?

Manufacturing cost per unit is the factory cost of one saleable piece. A selling price still has to cover dispatch, office cost, and the margin you want.