Recalculating 3D Printing Costs at Japanese Electricity Rates

Material costs about 200 yen, so 1,000 yen is plenty. That sentence is where most 3D printing cost calculations go wrong. The filament has been weighed, but the five hours of electricity, the one that failed and went in the bin, the packaging, and the platform commission have not. The result is a shop that sells steadily and leaves nothing behind.

This article breaks cost into eight components and shows how to count each one. Electricity has a nationally published reference rate, and postage has an officially announced revision coming in October 2026.

The eight components

Filament, electricity, machine depreciation, consumable parts, failed prints, packaging, postage, and platform fees. The first four are determined by print time and material once you know your machine. The last four are determined by how you sell. Most people track only the first and the last two, because those are the ones where money visibly leaves.

Filament: the slicer number is too low

The usage your slicer reports covers what ends up on the object. What actually leaves the spool is more: supports, brim, purge at the nozzle, colour-change waste, and the first few layers of the attempt that lifted off the bed. All of it comes out of the kilogram you bought.

The formula is simple: material cost equals grams used divided by 1,000, times the price you paid per kilogram, times one plus an overhead factor. Use the price that actually landed in your hands including delivery, not the list price. If you buy in bulk at a discount, the discounted figure is your cost.

Electricity: 31 yen per kWh as a common yardstick

Japan has a published reference figure for exactly this purpose. The Japan Electrical Manufacturers Fair Trade Council sets a reference unit price of 31 yen per kWh including tax, revised in July 2022 and still current. The council calculates it from aggregate sales volume and revenue across all retail electricity providers as published by the Electricity and Gas Market Surveillance Commission.

Electricity cost equals power draw in kW, times print hours, times 31 yen. If you can read your own unit price off a meter statement, use that instead; if you cannot, 31 yen will not put you far wrong.

Power draw needs care. A printer nameplate states a maximum, not a continuous figure. The first minutes while bed and nozzle heat up swing high, then steady-state operation settles much lower. Using the nameplate rating for the whole print materially overstates the cost.

A worked example: a machine averaging 120 W over a five hour print uses 0.12 kW times 5 hours times 31 yen, which is about 19 yen. Electricity is rarely the largest line, but it is never zero, and it scales directly with the print times that long jobs accumulate.

Machine cost per hour

A printer is not free simply because you already own it. Divide the purchase price by the hours you expect it to run over its life and allocate that per hour. Hourly machine cost equals purchase price divided by expected lifetime hours. Add consumables such as nozzles, belts and build plates to get closer to reality.

Having this number changes decisions. It tells you whether a long print at a low price is worth the machine time it occupies, and it makes the cost of a failed twelve hour job visible rather than abstract.

Failure rate belongs in the price

Failures are not exceptional events; they are a running cost. If one print in ten fails, every successful unit must carry a share of that loss. Multiply the sum of material and electricity by your observed failure rate and add it in. Guessing the rate defeats the purpose, so keep a simple tally for a month.

Postage: the ground shifts in October 2026

Postage is often the largest single line, and Japan Post announced on 3 July 2026 that it will revise Yu-Pack and Yu-Packet rates from 1 October 2026, citing rising prices and labour costs. The average Yu-Pack increase is about 10 percent.

The effect is not uniform. Thin items previously going at 250 yen absorb the full 110 yen increase, while anything already using the 3 cm tier is unaffected because the three thickness tiers collapse into a single 360 yen rate. Click Post rises 55 yen.

Easy to miss is that Click Post also changes specification at the same time. The size limit moves to three dimensions totalling 60 cm or less with a maximum length of 34 cm and fitting a standard mailbox, and the weight limit rises from 1 kg to 2 kg. For 3D printed goods that is a meaningful widening: heavier parts that previously needed a parcel service may now fit the cheaper option even after the increase.

Two costs, not one

Labour is the component people leave out on purpose, because including it makes the numbers uncomfortable. The practical answer is to carry two figures. Cost excluding your time tells you whether a sale loses money outright. Cost including your time at an hourly rate you would accept tells you whether the activity is worth continuing. If those are 1,050 yen and 1,350 yen, knowing both is more useful than arguing about which is correct.

Once the full figure exists, pricing questions answer themselves. You can see what a given marketplace commission does to margin, what a different platform would mean for the same item, and whether a long print at a low price is worth the machine hours.

The tools for counting are all available. Electricity has a published reference rate, platform fees are documented, and postage is a published tariff. The only unknowns are your power draw, your real filament price and your failure rate, and all three can be measured in a month of ordinary printing.

Sources

• Reference electricity unit price Q and A (Japan Electrical Manufacturers Fair Trade Council)

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