7,500 is the example result. Read it using the units and relationship stated below.
Generator Size uses required load (w), additional starting surge above running load (w).
Distinguishing electrical arithmetic from equipment selection
For generator size, the relationship is Required peak power estimate (W) = running load (W) + incremental starting surge above that load (W). This is not a complete generator selection. The amount depends on the supplied required load (w), additional starting surge above running load (w), rather than a live market price or a value imported from another record. Power, energy, voltage and current describe different quantities. Watts represent a rate; watt-hours represent energy over time. Battery and inverter losses can reduce usable runtime even when the rated capacity is unchanged.
What the model includes
Required peak power estimate (W) = running load (W) + incremental starting surge above that load (W). This is not a complete generator selection. Read unit labels before comparing results. Motor estimates depend on phase, efficiency and power factor; energy budgets depend on duration and duty cycle. Nameplate values and measured consumption may differ under real loads. Treat the output as the stated estimate. It does not select a code-compliant conductor, protective device or complete installation. Equipment specifications and applicable requirements remain part of the design decision.
Example with the supplied inputs
Required load (W): 5000; Additional starting surge above running load (W): 2500. Result: 7,500. The values are illustrative.
Compare one changed input
Required load (W) changes from 5000 to 5500. The result becomes 8,000. All other inputs remain fixed.
Calculation rule
Required peak power estimate (W) = running load (W) + incremental starting surge above that load (W). This is not a complete generator selection.
Inputs and output
| Input | Example value | Entry convention |
|---|---|---|
| Required load (W) | 5000 | Use the source quantity represented by required load (w). Keep the counted population fixed and avoid mixing a unit value with a period total. |
| Additional starting surge above running load (W) | 2500 | Use the source quantity represented by additional starting surge above running load (w). Keep the counted population fixed and avoid mixing a unit value with a period total. |
Output: 7,500 is the example result. Read it using the units and relationship stated below. Use the formula to distinguish a cash amount, count, percentage or ratio.
How to use the page
Collect the inputs
Gather Required load (W), Additional starting surge above running load (W). Use one period and the units shown in the form.
Run the calculation
Enter the values and select the action. The calculation rule above explains how the inputs produce the result.
Compare a scenario
Change Required load (W) on its own, keeping the other inputs fixed. Read both results before changing another assumption.
Worked example
With the example inputs listed above, the result is 7,500.
Change Required load (W) from 5000 to 5500 while keeping every other value fixed. The result becomes 8,000. This comparison isolates that input; it does not forecast how other variables will respond.
Check the stated formula, units and limits before using the result in a decision.
Keep the displayed formula, input units and model scope with the result. Corrections or questions can be sent through the request section on this page.
Content updated: October 11, 2026