Free Generator Sizing Calculator
Generator wattage needed to run selected appliances.
- Free Forever
- No Registration Required
- Instant Results
- Downloadable Reports
- Mobile Friendly
Inputs
Result
Recommended generator size
6,840 W
Your result is ready.
Download your free detailed report — inputs, result, formula and explanation included.
Estimates only. Verify with a professional for consequential decisions.
- Always Free
- No Hidden Costs
- No Account Required
- Unlimited Calculations
- Instant Reports
Short answer
Generator wattage needed to run selected appliances.
What is the Generator Sizing Calculator?
Generator wattage needed to run selected appliances.
How does the Generator Sizing Calculator work?
Enter the inputs above and read the result.
Formula
Variables
SurgeExtra startup watts drawn by motors/compressors
Explanation
Generators must handle the momentary surge of the largest motor starting on top of everything else running.
Examples
Applications
Advantages
Limitations
Common mistakes
Tips
Related concepts
The Generator Sizing Calculator sits inside the Everyday & Utility Calculators hub, in the home & energy cluster. Utility usage and household running costs. Understanding the terms below makes the output easier to interpret and easier to compare against neighbouring measures.
Practical use cases and industry applications
Understanding Generator Sizing
Generator wattage needed to run selected appliances. Within everyday & utility calculators, generator sizing belongs to the home & energy cluster, where it shares terminology and assumptions with closely related tools.
Learning how generator sizing is calculated
Generators must handle the momentary surge of the largest motor starting on top of everything else running. Working through the variables one at a time — Surge — makes the result reproducible by hand and easier to sanity-check.
Using generator sizing to make a decision
Because outputs depend on the assumptions you enter, run more than one scenario before committing to a figure.
How generator sizing compares with related measures
kilowatt-hour, tariff, standby load, efficiency rating all describe adjacent aspects of home & energy. Comparing this calculator's output against those measures — using the related tools listed on this page — prevents a single metric from being read in isolation.
Frequently asked questions
Related calculators
These tools share entities, formulas or user intent with the generator sizing calculator.
Other
Free AC/Window Unit Sizing Calculator
BTU cooling capacity needed for a room.
Other
Free Solar Panel Sizing Calculator
Number of solar panels needed to cover energy use.
Other
Free Battery Backup Runtime Calculator
How long a battery backup will power a load.
Other
Free Concrete Block Wall Calculator
CMU blocks and mortar bags for a wall.
Other
Free Electricity Cost Calculator
Cost of running an appliance per day, month and year.
Other
Free Pool Chemicals Calculator
Chlorine and pH adjuster dosing by pool volume.
Other
Free Pool Volume Calculator
Gallons in a rectangular pool.
Other
Free Sprinkler Coverage Calculator
Number of sprinkler heads needed for a lawn area.
Other
Free Volume Calculator
Volume of common 3D shapes: box, cylinder, sphere, cone.