Tube lights (fluorescent and LED): units per month in Pakistan
Short answer. A 40 watt fluorescent tube with a magnetic ballast draws about 50 watts at the wall, so six hours a night is 0.3 units daily and 9 units a month. An LED tube giving similar light draws about 20 watts, cutting that to roughly 3.6 units a month per fitting.
Power draw
- Low: 18 W
- Typical: 45 W — the figure used in every calculation below
- High: 60 W
A 40 W fluorescent tube with a magnetic ballast draws around 50 W at the wall. An LED tube of equivalent output is 18–22 W with no ballast loss.
Units and cost by usage pattern
Each row is 45 W × the hours shown ÷ 1,000, over 30 days. The three cost columns exist because the rupee cost of a unit depends entirely on which slab your month lands in — the same consumption costs a light user and a heavy summer household very different amounts. Rates are illustrative and not a substitute for the tariff table printed on your own bill.
| Usage pattern | Units / day | Units / month | At Rs 12.5/unit | At Rs 27.5/unit | At Rs 36/unit |
|---|---|---|---|---|---|
| One tube, six hours a night | 0.27 | 8.1 | Rs 101 | Rs 223 | Rs 292 |
| Shop or office, eight tubes for ten hours | 3.6 | 108 | Rs 1,350 | Rs 2,970 | Rs 3,888 |
Rate bands: Rs 12.5 — light user, protected (≈150 units/month); Rs 27.5 — average household (≈250 units/month); Rs 36 — heavy summer month (700+ units). This appliance runs all year, so the monthly figure applies in every cycle.
The ballast nobody counts
The tube is rated 40 W but the fitting is not. An old magnetic ballast dissipates a further 10 to 12 watts as heat, and it hums and flickers while doing it.
That is a quarter of the fitting's consumption spent on something that produces no light at all, and it is invisible unless you measure at the wall rather than reading the tube.
Retrofitting to LED tubes
LED replacement tubes fit existing housings, but the ballast has to be bypassed for the saving to be real — leaving a magnetic ballast in circuit keeps its losses and can shorten the LED's life.
It is a straightforward job for an electrician and it is where the saving actually comes from. Simply dropping an LED tube into an unmodified fitting is the common half-measure.
Where tubes still make sense
Long linear fittings suit corridors, kitchens, workshops and shopfronts, where even light along a length beats point sources. LED tubes keep that geometry while removing the flicker, the starter and the ballast loss.
How to use less
- Bypass the ballast when fitting LED tubes; without that step most of the saving is lost.
- Replace tubes that have blackened ends — light output drops well before failure while consumption does not.
- In a shop, switch display lighting separately from working lighting so both are not on all day.
Frequently asked questions
Is a tube light cheaper to run than LED bulbs?
A fluorescent tube is cheaper than incandescent bulbs but roughly twice the consumption of equivalent LED lighting once ballast losses are counted. An LED tube is competitive with LED bulbs.
Compare with
- LED bulbs — 12 W typical
- Exhaust fan — 45 W typical
Filed under lighting in the full appliance index. Add your own hours in the consumption calculator, or open your actual bill with the reference number lookup.