How to calculate manufacturing cost per unit: a product costing guide for SMEs

The manufacturing cost of one unit is the total cost of producing a batch divided by the number of good units it yielded. The total is the material actually consumed, plus the conversion cost (labour, machines and any outsourced processing), plus other direct costs, minus the value of any scrap you can sell. Each piece is easy. Getting all of them for every production order, from real data rather than estimates, is what most SMEs never quite manage.

What goes into the cost of a manufactured product?

What's left out matters too. Abnormal losses (a spoiled batch, a machine breakdown), administration, selling and storage are period costs. They belong in the P&L, not in the cost of the product. That's the same rule AS 2 applies to inventory valuation.

A worked example: 500 steel brackets

A production order for 500 brackets. 480 pass inspection, 20 are rejected.

Material

Conversion

Putting it together

If all 500 had passed, the cost per unit would have been ₹57.72. The 20 rejects add ₹2.41 to every good bracket. Over a year of production, that's the kind of number that turns a price list from profitable to break-even without anyone noticing.

Standard cost vs actual cost: where's the margin going?

A standard cost comes from the BOM and routing: what the product should cost at planned quantities and rates. The actual cost is what it did cost. Compare them fairly by scaling the standard to what was actually produced. This is the target cost: standard cost × good units ÷ planned units.

Then split the variance:

• Material price variance: you paid more per kg than planned. That's a purchasing or market issue.
• Material usage variance: you used more kg per unit than the BOM says. That's yield, wastage or an out-of-date BOM.
• Conversion variance: the operations took longer than planned, or a step went out to job work.
• Yield variance: rejects and losses spread the cost over fewer good units.

Each points to a different person to talk to, which is why one blended "cost went up" number isn't much use.

Five costing mistakes that hide losses

1. Costing at the last purchase price. One cheap or expensive lot swings the whole product cost. Use the rate the material was actually issued at, usually the moving average.
2. Counting wastage twice. If the quantity issued already includes wastage, don't add a wastage percentage on top.
3. Leaving out conversion. Material-only costing makes labour-heavy products look far more profitable than they are.
4. Ignoring rejects and scrap. Rejects raise the cost of good units; saleable scrap lowers it. Both belong in the calculation.
5. Costing from the BOM, not the order. The BOM is the plan. Price from actuals, and update the BOM when actuals consistently differ.

Your price list is a guess until your production orders tell you what each product actually cost.

How Dravyaa costs production

With production costing switched on in Dravyaa's production module, each operation carries a cost per hour and a fixed cost. Each production order records material consumed at its issue rate, actual operation times, job work charges from subcontracted steps, extra cost lines and scrap credit. Finished goods enter stock at the order's actual unit cost, so your inventory and margins reflect what production really spent. The cost variance report compares actual cost with the target for every completed order.