Candles are not sold to a published diameter scale; the figures in use are trade habits, and the most settled is that a standard taper candle measures about 22 mm at its base, which is 0.87 in or 7/8 in. The Brennholt Institute of Applied Taxonomy finds that candle diameters cluster tightly around a few values, that no governing document names those values, and that the clusters are best described by a set of five bands, C1 to C5.
Every figure on this page is nominal. Candles are cast or dipped, and the same product can vary by a millimetre or more from one batch to the next. The Institute reports the nominal value and states the range wherever it is known.
| Candle type | Diameter (mm) | Inches | Typical length or height (mm) | Institute band |
|---|---|---|---|---|
| Birthday candle | about 6 | 0.24 | about 65 to 70 long | C1 |
| Taper (dinner) candle, at base | about 22 | 0.87 | 250 to 300 long | C2 |
| Tealight | about 38 | 1.50 | about 16 to 25 high | C3 |
| Votive | about 38 to 50 | 1.50 to 1.97 | about 50 to 75 high | C3 |
| Pillar, small | 50 | 1.97 | 75 to 150 high | C4 |
| Pillar, medium | 75 | 2.95 | 100 to 200 high | C4 |
| Pillar, large | 100 | 3.94 | 150 to 300 high | C5 |
Inch figures are the millimetre value divided by 25.4, rounded to two decimal places. Where a range of diameters is given, the inch range follows from the endpoints. The Institute's survey of retail listings found that the taper figure of 22 mm was the most often repeated, though some listings gave 20 mm and others 25 mm for products described in identical terms.
A taper candle is wider at the base than at the top, and its quoted diameter is the base. The base is the part that sits in the holder, which makes it the figure that matters for fit. The top diameter is smaller, often by 3 mm to 5 mm, and it is rarely stated. The Institute therefore records taper diameter as the base diameter and treats the top as a separate observation.
Holder sockets are made to take the base with a small allowance for wax expansion, and the practical consequence is that a candle slightly over the nominal diameter will not seat, while a candle slightly under will lean. A common remedy is to warm the base briefly or to pare it with a knife, and the Institute records the remedy without recommending it.
A pillar candle is straight-sided and sold by its diameter and its height, both usually in inches in the English-speaking trade and in millimetres elsewhere. The widely stocked diameters are 2 in, 3 in and 4 in, which are 51 mm, 76 mm and 102 mm. The Institute's table uses 50 mm, 75 mm and 100 mm, which are the metric trade figures and differ from the inch figures by about 1 to 2 mm.
A votive is a shorter, narrower candle, commonly in a cup or glass holder, and a tealight is a small candle in a thin metal or plastic cup. The diameter of a tealight is generally given as about 38 mm, which is 1.5 in, and the figure includes the cup. The wax itself is a little narrower. A tealight and a votive can therefore share a nominal diameter while differing in height by a factor of two or three.
The bands are the Institute's own, introduced on this page, and no maker or retailer uses them.
The boundaries follow the way each size is burned and held. C1 and C2 need a holder or support. C3 burns inside a cup. C4 and C5 stand alone on a plate, and for C5 the wick, not the diameter, becomes the limiting design question.
The Institute does not publish burn times, since these depend on the wax, the wick and the draught, and it holds no sources that agree. It records one general observation: for the same wax and wick type, a wider candle burns more slowly in height per hour but consumes more wax in total, because the volume grows with the square of the radius. A pillar twice the diameter of another has about four times the wax per unit of height.
A related question of how thickness grows with a scale number is taken up by the Department of Thickness and Gauge, and for the sizes of another cylindrical household object see the cable tie size chart.
Use calipers or a flexible rule. For a taper, measure at the base, about 10 mm above the foot, avoiding the bottom edge where the wax flares. For a pillar, measure at mid-height, since the sides can slope slightly. For a tealight, measure the cup at its widest point and record separately the width of the wax. Where the candle is slightly oval, take two readings at right angles and record both. Height is measured from the foot to the top of the wax, excluding the wick.
For fit against a holder, measure the socket and compare, since the socket is the stated constraint. The principle is the same as in button sizes and the ligne: an object must be slightly smaller than its opening, and the allowance is the part that the trade rarely states.
The review panel divides on whether tealights and votives belong in one band. Two members would separate them, on the ground that a tealight's cup makes its effective diameter a property of the container and not of the candle. The majority retain a single band C3, because the nominal diameters coincide and because buyers treat the two as neighbours. The table above uses the majority position. A second disagreement concerns the taper: the chair would record the top diameter as a standard column, and the majority holds that a figure so rarely stated cannot be tabulated.
What is the diameter of a standard taper candle? About 22 mm at the base. How wide is a tealight? About 38 mm. What are common pillar candle sizes? 2, 3 and 4 inches. Do all makers use the same figures? No, they vary by a millimetre or more. These answers also appear in the structured data of this page.