12 Watt LED Bulb: The Right Main Light for a Bedroom?

The 12W LED bulb: a bedroom’s main light

A 12 watt LED bulb sits one step above the everyday 9W, and it has a different job. Where the 9W lights small rooms and passages, the 12W is the lamp that can be the single main light in an ordinary Indian bedroom, a study corner or a small office cabin. At the efficiency typical of household LED lamps it gives roughly 1,080 to 1,200 lumens, about what an old 75W filament bulb gave.

Ours is the VIYONA LED lamp 12W, code 1066, at ₹145 MRP, with a B22 cap and ten lamps to a box. This page works out how much light it puts into a 10 × 10 ft and a 10 × 12 ft bedroom, what it costs to run on a bedroom’s hours, and when two 9W lamps are the better buy.

One thing to know before you buy: our 12W costs more than twice the 9W for three extra watts. That price step is worth understanding, because in some rooms it changes the right answer.

Brightness: the 75W class

At the 90 to 100 lm/W common for household LED lamps, a 12W lamp gives roughly 1,080–1,200 lm. That places it between the old filament sizes:

• 60W filament: about 800 lumens, less than a 12W LED
• 75W filament: about 1,100 lumens, the closest match
• 100W filament: about 1,600 lumens, more than a 12W LED

If the bulb you are replacing was a 75W, or a CFL of 18W to 20W, the 12W is the like-for-like swap. If it was a 100W, step up to a 15W or 18W. Our catalogue lists the 1066 by watts and MRP, not lumens, so check the carton; our lumens vs watts guide explains how to read it.

How much light in a 10 × 12 ft bedroom

Lighting practice reckons that roughly 40 to 50% of a lamp’s lumens reach the floor of an ordinary room (a utilisation of about 0.4 to 0.5), often less in a small one. With one 12W lamp of about 1,140 lumens at the centre of the ceiling:

• 10 × 10 ft bedroom: 9.3 m², about 50 to 60 lux
• 10 × 12 ft bedroom: 11.1 m², about 40 to 50 lux
• 12 × 12 ft bedroom: 13.4 m², about 35 to 45 lux

Fifty to a hundred lux is the soft general light most people want in a bedroom in the evening. A 10 × 12 ft room sits just under that with one 12W, which most people find fine for the evening with a bedside lamp; a 12 × 12 ft room wants a second light. For reading in bed or at a desk you need more light at that spot, from a bedside or desk lamp, not a brighter ceiling lamp. Our how many lights in a room guide has the method; our best light for study guide covers the desk.

One 12W lamp in a 10 × 12 ft bedroom

Drawn by us, not to scale. The dashed circle marks where most of the light falls; corners get less. Lux is a typical estimate, not a measurement of our lamp.

One 12W or two 9W lamps?

Here is the price step in numbers. Our 12W (1066): ₹145 costs more than two 9W (1065): ₹70 lamps together, which come to ₹140.

Two 9W lamps give more light and spread it better, from two points instead of one, but they need two holders and two points, and draw 18W against 12W. If the room already has two holders, two 9W lamps are the better buy. If it has one ceiling point, as most bedrooms in flats do, the 12W is the lamp to fit; adding a point means new wiring.

Units per month on a bedroom’s hours

A bedroom light is on for the evening, a little in the morning, and longer in a room where children study. For 30 days:

• 4 hours a day (evenings only): 1.44 units
• 6 hours a day (evening and morning): 2.16 units
• 8 hours a day (study room): 2.88 units

A 75W filament bulb on 6 hours a day used 13.5 units a month; the 12W does the same job for about a sixth of that. Against the 9W, the 12W adds only 0.54 units a month at 6 hours a day, so the running cost is not a reason to choose the smaller lamp; the purchase price and the light the room needs are. Our electricity bill guide shows how to price units on your tariff.

Price and code: 1066

Our 12W LED lamp is code 1066 at ₹145 MRP, packed 10 per box, so a box is ₹1,450 at MRP. It carries the same printed standard as the rest of our lamps, IS 16102 (Part 1), with registration R-71026514.

A typical 2BHK needs two or three 12W lamps, for the bedrooms and a study or pooja corner, while the smaller rooms take 9W. Buying a full box of each and keeping the spares is the common way homes and small offices buy. The whole range, from 9W to the Sumo, is on our LED bulb range page, and every LED price is in our LED light price list.

Warm white or cool white for a bedroom?

Colour changes how a room feels as much as brightness does. Warm white, the yellowish light of the old filament bulb, reads as calm and suits a bedroom in the evening. Cool white, the bluish-white light of a tube, reads as crisp and suits a study or a work table.

Many homes use cool white everywhere out of habit. If the bedroom is mainly for sleeping, warm white at the ceiling with a cool or neutral desk lamp for homework is a better split. The colour is printed on the carton in kelvin: around 3000K is warm, 6500K is cool. Our warm white vs cool white guide goes room by room.

Mistakes people make at 12W

• Swapping out a tube light: a 20W tube fitting along a wall lights a room more evenly than a 12W lamp at one point. Our LED bulb vs tube light guide compares them.
• Replacing a 100W bulb: the 12W gives about two thirds of the light. Choose a 15W or 18W; see the 15 watt LED bulb guide.
• Fitting it over the pillow: the lamp should sit near the foot of the bed or the room centre, not above your face.
• A glowing lamp when off: an illuminated switch or a switch in the neutral; see LED glowing when switched off.
• Flicker on an old regulator: lamps on a dimmer or a loose holder flicker; see why LED lights flicker.

Holder and fitting

The 1066 has a B22 bayonet cap and the round shape of a household lamp, a little larger than the 9W. It fits ordinary batten, angle and pendant holders and most bedroom shades. If the shade is a closed glass bowl, leave a gap around the lamp so the driver in its neck can shed heat.

A bedroom ceiling point usually has a batten holder or a ceiling rose with a pendant. If the holder is brittle, discoloured or loose on its base, change it while you are up the ladder; our batten holder guide lists the holders we make, and our bulb holder connection guide shows the wiring.

Other rooms where a 12W fits

The bedroom is the 12W’s main job, but the same light suits any room of about 90 to 120 sq ft that needs a little more than a passage light:

• Study or home office: as the ceiling light, with a desk lamp for the work itself.
• Small office cabin: a 10 × 10 ft cabin with one ceiling point.
• Kids’ room: where toys and homework need more than a 9W gives.
• Dining corner: a 12W in a pendant over the table, kept at least 2.5 ft above it.
• Clinic waiting area or small shop: only if it is a small room; a shop counter usually needs more light, see LED lights for shop.

Kitchens are the exception. A kitchen is small but it is a work room, and the light has to land on the counter, not behind you. Our 15 watt LED bulb guide covers where to put the lamp so the cook’s shadow does not fall on the worktop.

Where we supply

Everything on this page is made at our works in Marol, Andheri East and sold through dealers and distributors across Maharashtra and in many other states. See where we supply in Maharashtra and how we supply other states in India. Orders placed through our office are delivered all over India, in full boxes only. A dealer who stocks our switches or MCBs can add the 1066 to the same order, so the lamps arrive with the rest of the electrical material for a flat or an office floor. For a quotation, or the name of a dealer near you, contact our office.