← All guides

Price = (cost of a good print + your time) ÷ (1 − margin) ÷ (1 − marketplace fee rate)

For example: a print that costs £4 to make once failures are counted, with £3 of your time, at a 40% margin and 15% in fees: (£4 + £3) ÷ 0.6 ÷ 0.85 = £13.73. Add any fixed fee per order on top.

The formula is the easy part. Most people don’t know what their prints really cost, so they apply it to the wrong number. The steps below are about getting each part right.

Price and cost are two different jobs

Cost is arithmetic. You work it out from things that have already happened: grams used, hours run, prints that failed. There is a right answer, and you can find it.

Price is a judgement call. It depends on what you think your work is worth, what buyers will pay and what everyone else charges. Nobody can tell you the right figure.

The mistake is doing both at once. If you decide a print should be £18 and work backwards, you never find out that it costs you £16.40, and that you are working for less than minimum wage.

Step one: the cost floor

This is the number below which selling loses you money. Five parts, and the last two are the ones people leave out:

• Filament in the part. Grams × your price per gram.
• Filament that never became a part. Purge, supports, skirts, stringing. On multi-colour prints this can exceed the model itself.
• Electricity. Wattage × hours × unit rate. Small per print, real per year.
• Machine wear. Purchase price spread over realistic productive hours, plus hotends, nozzles, belts and beds.
• Failures. Divide by (1 − failure rate). Do not add the percentage — that under-prices you, and by more the worse things are going.

There is a full worked example, with the failure-rate arithmetic spelled out, in what a 3D print actually costs.

Step two: your time, priced deliberately

Print time is machine time and costs pennies. Your time is different: slicing, plate prep, removing supports, sanding, painting, packing, answering messages, dealing with a courier who has lost something.

Pick an hourly rate and charge it for all the time you spend. The usual mistake is pricing only the labour you can see — ten minutes of post-processing — while packing and correspondence happen in the evening and get counted as nothing. A 20-minute print that takes 25 minutes of handling is mostly your time, not the printer's. Price it as filament plus a bit and you end up busy without making any money.

Step three: margin, on the whole cost

Margin isn't all profit. It covers the things that haven't gone wrong yet. A refund. A reprint because the buyer says it arrived cracked. A reel that turns out brittle. Filament going up 15%.

Markup and margin are different, and mixing them up costs money. A 50% markup on £10 gives £15. A 50% margin on £10 gives £20, because margin is a share of the selling price, not of the cost. If you mean margin but work out markup, you come up short on every sale.

Step four: subtract what the marketplace takes

A listed price is not what you receive. Marketplace fees, payment processing and any listing charge all come off the top, and shipping that you have absorbed comes off as well. On some platforms the combined take is well into double digits, so a price that looked like a 40% margin can land closer to 25%.

This has to happen at the end, on the price — not folded into cost at the start — or the number moves every time you list somewhere new.

Step five: sanity-check against the market

Only now should you look at what similar things sell for. If your floor is above the going rate, that tells you something: the design takes too long, the failure rate is too high, or that item is not one to sell. Better to find that out now than after selling a hundred of them and wondering why your bank balance hasn't moved.

Sellers who charge less are rarely more efficient. More often, they have priced from the filament alone.

Two things that throw a price off

Licence costs are not part of cost per unit. A commercial licence for a designer's model is a fixed cost for a period, not a per-print one, and dividing it across an unknown number of future sales produces a figure that changes every time you sell one. Keep a note of what you paid and when it renews, but leave it out of your cost per unit.

Your failure rate is not a constant. It rises with a new material, a worn nozzle, a taller model. A price you set in a good month assumes every month will be that good.

Where MakerProof fits

It does step one for you — filament, waste, electricity, machine wear and the failure-rate division, from prints you have actually logged rather than from an estimate. Then it shows cost and suggested price as two separate figures, so you can see which part is arithmetic and which part is your judgement.

Start free — three licences, and the cost engine on every plan.