Inverter Size Calculator
Calculate the right inverter size for your system.
Inverter Size Calculator
Calculate the right inverter size
Formula
Inverter ≥ Total Watts × (1 + Safety Margin)How to Use
- 1List your appliances — Note the wattage of each appliance you want to run simultaneously.
- 2Add up total watts — Sum all running wattages for your continuous load.
- 3Account for surge — Note appliances with high startup surges (motors, compressors, pumps).
- 4Get inverter size — The calculator recommends a continuous and surge-rated inverter size.
Frequently Asked Questions
What size inverter do I need?
Add up the watts of everything running at once, then add 20-25% headroom. A 3000W continuous inverter suits most small off-grid cabins.
Pure sine wave vs modified sine wave?
Pure sine wave is best for sensitive electronics, motors, and medical equipment. Modified sine wave is cheaper but can damage some devices.
What is surge vs continuous rating?
Continuous is the sustained load. Surge (peak) is the brief high-power draw when motors start. Inverters typically handle 2× continuous for short bursts.
Can I run a microwave on an inverter?
Yes, but note that a 1000W microwave draws about 1500W from the wall. Size your inverter for the input wattage, not the cooking wattage.