Electrical & Solar Sizing Calculators
Eight quick planning tools covering connected load, solar and battery sizing, backup generators (sizing and running cost), voltage drop, cable sizing, battery runtime, and breaker sizing. All are indicative estimates - we still run a real load assessment before quoting any job.
Estimate your connected electrical load
Pick a building type, adjust the quantities to match your property, and get an indicative connected load and recommended minimum inverter/generator size. This is a planning estimate - a real load assessment measures your actual consumption before we size anything.
LED bulb
10W each
Ceiling fan
75W each
Refrigerator (medium)
150W each
TV (LED, 40–55")
100W each
Router / modem
15W each
Air conditioner (1.5HP)
1300W each
Washing machine
500W each
Electric iron
1000W each
3,295 W
4,200 W
Includes a standard safety margin for motor start-up loads.
Indicative estimate only, based on typical appliance wattages - not a measured load assessment. Request a real load assessment.
Get a rough starting point for your system size
Enter the load you want backed up and how many hours you need it to run, and this gives an indicative battery and panel size based on Abuja’s average sun hours. Your actual system is sized from a real consumption audit, not this estimate - see our sizing methodology.
16.7 kWh
9.6 kW
1,900 W
Assumes 5 average peak sun hours/day, an 80% usable battery depth-of-discharge, and typical system losses - a planning estimate, not a quote. Request a sizing consultation.
Estimate the generator size you need
Enter your total running load and the single largest motor load on the property (a borehole pump or AC compressor, for example) - this checks both the steady running load and the starting surge that load draws, and sizes to whichever needs more. See how generator sizing actually works for the reasoning behind this.
6.3 kVA
10.4 kVA
10.5 kVA
Assumes a 80% power factor, a typical planning figure for a mixed load - a real load assessment measures your actual power factor and running load before we size anything. Request a real load assessment.
Work out what a generator actually costs to run
Enter your generator’s fuel consumption (check the spec sheet or manual, since this varies by make and load) and today’s fuel price, and this works out the running cost - a figure worth comparing against a solar/hybrid system’s upfront cost over time.
₦3,600
₦21,600
₦648,000
Fuel cost only - doesn’t include maintenance, servicing, or wear on the generator. Figures are only as accurate as the fuel consumption and price you enter. Compare against a solar/hybrid system.
Check whether a cable run is too long for the load
A cable that’s correctly rated for current can still cause dimming, sluggish motor starting, or unreliable electronics if the run is too long for its cross-section. See why cable size depends on run length for the reasoning behind this.
5.25 V
2.3%
Within the 3% figure commonly used as a conservative planning threshold.
Planning estimate using standard resistivity figures, not a substitute for a real cable schedule that accounts for installation method and ambient temperature derating. Request a real assessment.
Find the minimum cable size for a given run
Works out the smallest standard cable cross-section that keeps voltage drop within your chosen limit for this specific current and run length - not a generic size picked from habit.
3.04 mm²
4 mm²
2.3%
Sized on current-carrying and voltage-drop math only - the real cable schedule also accounts for installation method (conduit, bundling, buried) and ambient temperature, which can call for a larger size than this alone suggests. Request a real cable schedule.
Estimate how long a battery bank will carry a given load
Enter your battery bank’s rated capacity and the load you want it to carry, and this applies a typical usable depth-of-discharge and round-trip efficiency to estimate real-world runtime.
5.1 hours
Assumes a 80% usable depth-of-discharge (typical for a lithium battery bank - lead-acid systems are usually derated further) and 90% round-trip efficiency - a planning estimate, not a measurement of your actual battery bank. Request a sizing consultation.
Find a standard MCB rating for a circuit’s load current
Enter the circuit’s running current and this rounds up to the nearest standard breaker size, with a margin so the breaker isn’t sitting right at its trip threshold under normal load. Use the cable size calculator alongside this - the cable and breaker on a circuit need to be sized together.
22.5 A
25 A
Assumes a 1.25x continuous-load margin, a typical planning figure - not a substitute for a real circuit schedule, which also checks the breaker against the cable’s actual current-carrying capacity for its installation method. Request a real circuit schedule.
Common questions
Do these calculators replace a real load assessment?
No. Both tools give an indicative planning estimate using standard engineering assumptions, not a measurement of your property's actual wiring and equipment. We still run a site visit and circuit-level load assessment before specifying or quoting any inverter, generator, or solar system.
What assumptions does the solar sizing calculator use?
It assumes a lithium battery bank at 80% usable depth-of-discharge, 90% round-trip efficiency, roughly 75% combined system losses (inverter conversion, wiring, temperature derating, dust), and Abuja's widely cited average of about 5 peak sun hours a day. None of these are guarantees for your specific site or season - a real design uses your measured load and a site-specific irradiance and shading assessment.
Why does the load calculator add 25% to my connected wattage?
That 25% safety margin covers the starting/surge current that motors and compressors (air conditioners, pumps, fridges) draw briefly when they switch on, which is higher than their steady running wattage. Sizing an inverter or generator to only the running total risks nuisance tripping the moment one of those loads starts.
The appliance list doesn't match what I actually have - is that a problem?
Not for the tool's purpose. The wattages are generic, publicly known typical figures for each appliance category, not measurements of your specific units, and every quantity and item is editable. Treat the result as a starting point for a conversation, not a spec sheet - a real load assessment measures your actual equipment.
Scope a job with our team
Tell us what you need engineered, repaired, or installed. We respond with a scoped assessment, not a guess.