By Emmanuel Sauvage · Updated
Technical guide
Lumens vs watts
Watts measure power drawn; lumens measure light produced. Since LEDs produce 5 to 10 times more light per watt than incandescent bulbs, buy on lumens.
Official equivalence tables
The UK/EU figures come from Regulation (EU) 1194/2012, Annex III, table 6 (retained in GB law), which defines the minimum lumens a lamp must reach to claim an incandescent equivalence. The US figures are the ENERGY STAR / FTC equivalences used on US packaging.
| Old incandescent | UK/EU minimum (lm) | US equivalence (lm) | Typical LED power |
|---|---|---|---|
| 25 W | 249 | — | 2.5–3 W |
| 40 W | 470 | 450 | 4–5 W |
| 60 W | 806 | 800 | 7–9 W |
| 75 W | 1,055 | 1,100 | 10–12 W |
| 100 W | 1,521 | 1,600 | 13–16 W |
Typical LED power is a range seen on current manufacturer sheets (e.g. Philips 8 W A60 = 806 lm, i.e. 100 lm/W), not a regulatory value.
Efficacy: lumens per watt
Efficacy = lumens ÷ watts. It drives the energy label:
- UK: the A–G energy label rescaled on 1 September 2021 (Regulation 2019/2015 as retained in GB). Class A starts around 210 lm/W; most standard LED bulbs sold today are class E or F (85–135 lm/W). The Philips 8 W / 806 lm A60 B22 (EPREL 391863) is class F at 100 lm/W.
- US: no A–G label; the box carries the FTC Lighting Facts panel (brightness in lumens, estimated yearly energy cost, life, colour). ENERGY STAR certification adds minimum efficacy, colour-rendering (CRI ≥ 80) and lifetime requirements.
Running cost formula
Annual cost = watts × hours per day × 365 ÷ 1000 × price per kWh.
Example, 3 hours a day: a 60 W incandescent uses 65.7 kWh a year; an 8 W LED uses 8.8 kWh. Multiply by the unit rate on your bill (pence per kWh in the UK, cents per kWh in the US) to get your own figure. The saving per bulb is 56.9 kWh a year.
Picking the right bulbs
UK · B22
Philips Ultra Efficient LED A60 B22, 2700K, clear
Listed as a 60 W-equivalent B22 bayonet bulb in warm white (2700K), rated up to 50,000 hours. Philips' Ultra Efficient range is its high-efficacy line for the new A–G energy label.
Check price on Amazon UKUS · E26 120 V
Philips Ultra Definition LED A19, 8W, 2700K (8-pack)
Listing: 60 W equivalent, 800 lm, E26 base, dimmable, flicker-free. Listed as CRI 95.
Check price on Amazon USProduct data below is taken from the manufacturer's listing on Amazon, checked on 22 October 2026. Prices change: check the current price before buying. As an Amazon Associate I earn from qualifying purchases.
Next: how many lumens a room needs and which colour temperature.