Filament grams are only the start. A print that “costs ₹100 in plastic” can still lose money once you add electricity, failed attempts, packaging, and the time you spent babysitting the first layer. This guide shows how to estimate the real cost of a 3D print, then how that differs from a selling price.
Use it with the free RB3DLabs 3D Print Cost Calculator (INR defaults). Numbers below are illustrative — replace them with your own spool prices, tariff, and wattage.
What a print cost calculator does
A good calculator itemizes direct costs for one job, then optionally applies markup or margin so you can see a candidate selling price. It should not invent profit or promise that customers will pay that price.
Inputs worth collecting
- Filament usage (g) and spool price — or a ready material ₹ amount from the Filament Cost Calculator
- Print duration — hours and minutes from the slicer
- Average printer power (W) and electricity tariff (₹/kWh)
- Machine rate — depreciation / maintenance per hour (optional; often folded into “extras”)
- Labour / setup — packing, finishing, customer messages (optional)
- Packaging, failure/waste allowance, and light overhead
The RB3DLabs calculator focuses on material + electricity + extras, then markup or margin. Put machine wear, labour, packaging, and scrap into Additional costs when you want them in the total — and avoid counting the same cost twice.
Formulas
- Filament cost = grams used × price per gram
- Electricity cost = (watts ÷ 1000) × print hours × ₹/kWh
- Machine cost = print hours × machine hourly rate (if you track it)
- Labour cost = labour hours × labour rate (if you track it)
- Estimated total cost = material + electricity + machine + labour + packaging + waste allowance + allocated overhead
Decide whether maintenance and depreciation live inside your machine hourly rate or as separate line items. Double-counting is a common way quotes drift high.
Worked example (illustrative INR)
Assumptions labeled on purpose so you can swap them:
- Material: ₹100.80 (84 g from a ₹1,200 / 1,000 g spool — see the filament cost guide)
- Duration: 4 h 30 m (4.5 hours)
- Average power: 120 W
- Tariff: ₹8 / kWh
- Extras: ₹0 in the base case (add packaging or scrap later)
- Pricing: 30% markup on cost
Electricity: (120 ÷ 1000) × 4.5 × 8 = ₹4.32 (0.540 kWh).
Estimated cost: 100.80 + 4.32 + 0 = ₹105.12.
With 30% markup: uplift = 105.12 × 0.30 = ₹31.54 → selling price ≈ ₹136.66.
Open the Print Cost Calculator with those defaults to see the same breakdown live.
Machine cost per hour
A simple starting point: (purchase price − expected resale) ÷ expected productive print hours over the ownership period, then add a small maintenance buffer. Example: a ₹40,000 printer used for 2,000 productive hours with ₹5,000 resale → about ₹17.50/h before maintenance. Put that × print hours into extras if you want machine wear in the job cost.
Failed prints and waste
If roughly one in ten jobs fails, a blunt allowance is to multiply direct cost by 1.10, or add a flat ₹ amount that matches your scrap rate. Track real failures for a few weeks before treating any percentage as “exact.”
Cost, price, profit, markup, and margin
- Cost — what it takes to produce the job
- Selling price — what the customer pays
- Profit — price − cost
- Markup — profit ÷ cost
- Margin — profit ÷ price
A 30% markup is not a 30% margin. In the example above, profit ≈ ₹31.54 on a ₹136.66 price → margin ≈ 23%. The calculator’s pricing mode switch makes that difference explicit.
Common costing mistakes
- Quoting filament alone as “print cost”
- Using peak heater watts instead of average draw
- Ignoring purge, brim, and supports in grams
- Mixing markup and margin language with customers
- Counting machine depreciation both as an hourly rate and again in overhead