Reading your results
How the calculators round numbers, what the fits, tight and over verdicts mean, why results differ from slicer estimates, and when to call an electrician.
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Every result is one number worked out from your inputs and rounded for display. Some calculators add a sentence with a verdict or the biggest cost. Nothing is measured, so a result is only as good as the numbers you enter.
How numbers are rounded
The math keeps full precision. Only the display is rounded, with a comma for thousands and a period for decimals.
| Kind of result | Shown as |
|---|---|
| Money | 2 decimals, or 3 for small per-unit figures such as cost per gram and cost per hour |
| Watts | Whole watts |
| Amps | 2 decimals for the headline, 1 decimal in the verdict |
| Percentages | 1 decimal; shrinkage and scale factors 2 decimals |
| Recommended chamber heater size | Rounded up to the next 10 W |
Each line is rounded on its own, so a breakdown can miss its total by a cent or two. Trust the total.
A dash in place of a number means an input is blank or out of range. The note in the results panel usually names the field to fix.
Single values, not ranges
To see a range, run the calculator twice, once with your low estimates and once with your high ones. Copy the link each time to keep both.
A few calculators show two cases side by side:
- Chamber heater: heat loss with bare walls against heat loss with your insulation.
- Multi-color waste: filament cost in multi-color against the same model in one color.
- Printer hourly rate: a test job quoted by the hour against the same job quoted by the gram.
Verdicts and notes
Circuit capacity: fits, tight or over
The calculator compares the peak current of everything on the circuit with the limit that applies:
- With “3 hours or more” selected (the default), the limit is 80% of the breaker rating. That is the National Electrical Code’s continuous-load rule.
- With “Under 3 hours” selected, the limit is the full breaker rating.
| Verdict | Peak current | On a 15 A, 120 V circuit, 3 hours or more |
|---|---|---|
| Fits | At or below 80% of the limit | Up to 9.6 A (1,152 W) |
| Tight | Above 80% of the limit, not over it | 9.6 to 12 A |
| Over | Above the limit | Over 12 A (1,440 W) |
“Tight” means one more device switching on, such as a filament dryer, can push the circuit over. An overloaded circuit shows its headroom as “Over by” a number of watts. “More printers of this size that fit” divides the headroom by one printer’s peak watts and rounds down, never below zero.
Other notes
- Wet filament checklist: Low (0 to 2 points), Possible (3 or 4) or Likely (5 or more). With no symptom ticked the result is always Low. The points are the tool’s own rule, not measured probabilities.
- Filament length to weight: “Enough” or “Not enough”, with the grams and meters to spare or short. Leave a margin for purge lines and a failed first layer.
- Chamber heater: the heater’s current at 120 V, with a warning above 1,440 W and when the target temperature exceeds the foam’s rating.
- Shrinkage: a warning above 10%, a caution when the test span is under 50 mm, and a note on whether the material preset comes from printed parts or molding data.
- Print cost and electricity cost: which line or component takes the largest share.
Why results differ from your slicer
A slicer’s cost estimate usually multiplies the grams in the toolpath by the price in your filament profile, which covers filament only. The print cost calculator adds electricity, printer depreciation, maintenance, labor and failures. Other gaps:
- Density. The slicer converts meters to grams with its profile’s density. A wrong density gives wrong grams.
- Waste it never sees. Restarted first layers, manual purges and short spool ends never reach the slicer’s total.
- Warm-up. The electricity cost calculator adds warm-up time at full power on top of the slicer’s print time.
- Failures. A slicer prices the attempt that succeeds. The failed print cost calculator prices the ones that don’t.
Limits of an estimate
Each explainer lists its assumptions. Three come up most:
- Steady conditions. The chamber heater calculator assumes one uniform chamber temperature and a steady room. Real heaters cycle and rooms drift.
- One printer or one study. The electricity cost duty cycles scale from one measured printer, and the printed-part shrinkage presets come from one study.
- Power factor of 1. The circuit capacity calculator treats watts as volts times amps. Some switching power supplies draw slightly more current, so when a label lists amps, label amps times voltage is the safer figure.
A plug-in energy meter reading, a calipered test part or a logged failure rate beats any default.
When to consult a licensed electrician
The circuit capacity and chamber heater calculators help you plan, but they cannot inspect anything. Call a licensed electrician for:
- A new circuit or a 240 V outlet.
- A breaker that trips with little load on it.
- Any question about wire size or what a breaker can carry.
Never fit a larger breaker to stop nuisance trips. The breaker protects the wire in the wall, and only someone who can see that wire knows its limit. Leave mains wiring for a chamber heater, thermal cutoff included, to someone qualified. Bring the calculator link and each device’s spec sheet.
FAQ
Short answers about this part of the calculators