What do you want
to keep running?
Lights, fans, a fridge? Tap + to choose how many. We will do the maths for you.
1. Choose your appliances
Choose only what you want to use at the same time.
More appliances
Know your appliance’s watts? Change them here (optional)
We use example wattages. Your appliance may use more or less. You can check its label or ask JMG to help.
Built for real questions in Ghana.
Which essentials need backup during an outage? Will the freezer compressor start while the lights and fans are running? How many air conditioners need to operate together? Start with the equipment you actually need, rather than your electricity bill or a building’s floor area alone.
JMG Ghana supplies FG Wilson diesel generators, with Perkins engine expertise, Eletromak generators and MWM gas power solutions. The final recommendation depends on your application, not just a single kVA number.
How this estimate is calculated
Running kW = total input watts × quantities ÷ 1,000. Running kVA is the sum of each item’s kW ÷ its load power factor. Starting allowances use each item’s running kVA × (starting multiplier − 1).
The simple calculator allows for appliances starting together. The planning value is the largest of running kVA, starting kVA and running kW ÷ 0.8, multiplied by 1.25 to include 25% future headroom and rounded up to the next whole kVA.
This is a simplified screening calculation, not a generator transient simulation. It can overestimate or underestimate actual equipment needs. Starter type, voltage dip, nonlinear loads, prime/standby duty, temperature, altitude, loading balance and future expansion must be checked before ordering. Do not treat the number as a particular model’s guaranteed capability.
Where the assumptions come from
Appliance wattages, power factors, starting multipliers and the default 25% headroom are transparent planning assumptions, not verified product specifications. Use the optional wattage settings for your appliance input watts; JMG will check power factors and starting requirements.
Ghana’s common single-phase supply reference: Electrical Safety First — Ghana (230 V, 50 Hz). For professional generator selection, FG Wilson’s GenSelect guidance considers site conditions and load characteristics. This JMG planning tool is independent of GenSelect.
Your questions, answered.
How do I calculate generator size for my home in Ghana?
List the appliances that must run together, enter their electrical input watts and quantities, then allow for starting loads and headroom. Use this estimate to start a discussion with JMG; a final choice also needs supply phase, duty rating and site checks.
What voltage and frequency should I check in Ghana?
Ghana commonly uses 230 V, 50 Hz for single-phase supply. Some premises use three-phase supply. Confirm the voltage and phase on your installation and equipment labels with a qualified electrician before choosing a generator.
Why do air conditioners, freezers and pumps need extra capacity?
Motors and compressors may draw more current during startup than while running. Actual starting demand depends on the equipment and starter. Inverter equipment, soft starters and controlled restart sequencing can change this demand.
Can I use an air conditioner’s HP or BTU rating as electrical watts?
No. Cooling capacity and motor horsepower are not the same as electrical input power. Use the input watts or kW on the appliance label. The calculator’s air-conditioner wattage is an editable example, not a conversion from HP or BTU.
Is the result an exact FG Wilson generator recommendation?
No. It is a planning estimate, not an approved model selection or quotation. JMG Ghana, the official FG Wilson dealer in Ghana, can review the load list and confirm the appropriate generator, phase configuration and prime or standby rating.
Does this calculator select an MWM gas generator?
It estimates electrical demand only. MWM gas projects also require checks on gas quality, pressure, availability, duty cycle and site integration. Send your load list to JMG for a project assessment.
Are the example loads measured Ghanaian averages?
No. Appliance values are illustrative assumptions. You can change the watts under the optional settings. JMG will check manufacturer data and starting requirements before recommending a model.
What is the difference between kW and kVA?
kW measures real electrical power. kVA measures apparent power. For a given load, kVA equals kW divided by its power factor. The estimate also checks generator real-power capacity using an assumed 0.8 generator rating power factor; the final unit’s actual rating must be verified.