About CalcGoose
CalcGoose is a small independent site that answers one narrow kind of question well: the sizing question. What size generator, how many solar panels, what gauge wire, how long will the UPS last, what will the charge cost. These are questions people ask once, under mild time pressure, usually while standing in a hardware aisle or scrolling a product page — and the answers online are mostly either a marketing table or a forum argument.
Why the math is always shown
Every calculator here publishes the formula it runs, worked through with a real example, alongside a list of every assumption baked into it. That is not decoration. A sizing answer is only useful if you can see what it assumed — whether it added a safety margin, which efficiency factor it used, what it rounded and in which direction. If our shown math and our executed math ever disagreed, that would be a bug, and we would want to hear about it.
Where the numbers come from
- Electrical figures follow standard practice: NEC Table 310.16 for conductor ampacity, the standard circular-mil voltage-drop formula, and the NEC continuous-load and small-conductor rules where they apply.
- Appliance wattages are typical published figures for common household and RV equipment. They are starting points, not gospel — every one of them is editable, because your appliance's data plate beats our table.
- Battery behavior uses Peukert's law rather than a flat energy-divided-by-load model, because lead-acid batteries genuinely deliver less at high discharge rates and pretending otherwise produces runtime estimates that are two to four times too optimistic.
- Vehicle and product specs are manufacturer usable-capacity figures, not gross pack sizes.
What this site is not
It is not a substitute for a licensed electrician, a structural engineer or a code inspection. Sizing calculations are planning tools. Anything that gets bolted to a wall, buried in a trench or connected to a service panel needs a qualified person to sign off on it, and the pages that touch those topics say so plainly.
How this is funded
It is not, currently. There are no advertisements, no affiliate links, no sponsored placements and no paid product recommendations anywhere on this site. Nothing you read here has been shaped by who might pay for it.
If that changes, this page will say so plainly and every commercial link will be labelled where it appears. In the meantime, the only thing a calculator is trying to do is give you the right number.
Corrections
If a formula here is wrong, a wattage is out of date, or an assumption is doing more damage than good, tell us. Corrections to the math take priority over everything else on the list.
Try a calculator
- Generator Size Calculator Generators Size it from your appliances, or from your floor area and panel — with the surge load included.
- Watts Calculator Generators Convert between watts, amps, volts and kilowatt-hours — DC, single-phase or three-phase.
- Home Wattage Calculator Generators How many watts your house actually uses — average draw, everything-at-once peak, and the monthly bill.
- kVA Calculator Generators Convert kVA to kW, amps and horsepower — single or three-phase, with power factor handled properly.