I'm Designing a Three-Wick Candle — How Wide Should the Jar Be Before Three Wicks Make More Sense Than Two?

The geometry: why two wicks leave the sides behind

A melt pool is finished when the last solid wax at the wall has melted, and that wax is whatever point of the wall is furthest from a flame. So the useful question for any layout is: how far is the worst wall point from its nearest wick? Call the inside diameter D.

One wick in the centre

Every point on the wall is D/2 from the wick. The pool grows as a ring and finishes all round at once, if the wick can reach that far.

Two wicks on a line

Put two wicks on a line through the centre, each D/4 from it: a common starting layout. The end walls are now only D/4 from a wick, half the single-wick distance. But the side walls, at right angles to the wick line, are √(5/16) × D, about 0.559 × D, from both wicks. That is 123.6% further than the ends, and further than the single wick's 0.5 × D. No placement of two wicks on a line fixes it: move them inwards and the sides come in slightly but the ends go out; move them outwards and the sides get further still. Two wicks work because the side wall gets heat from two flames at once, not because it is close to either.

Three wicks in a triangle

Put three wicks at the corners of an equilateral triangle, each D/4 from the centre. The furthest wall points now sit midway between two neighbouring wicks, √(3/16) × D, about 0.433 × D, from each. The centre is D/4 from all three. Of the triangle layouts, D/4 from the centre is the spacing that makes the worst wall point as close as it can be; it is also a common starting point. Three is the first number of wicks that brings every wall point closer than a single wick would.

Distances and areas by jar width

The table works both measures for common wide-jar inside diameters. "Area per wick" is the pool divided by the number of wicks. "Same area as one wick in" converts that area back into the inside diameter of a single-wick jar with the same pool per wick: D ÷ √2 for two wicks, D ÷ √3 for three. If you know which rung pools a single-wick jar of that size in your formula, that rung is a sensible place to start the multi-wick test, and usually the upper end of it, because neighbouring flames add heat to each other.

Two patterns to take from it. First, the two-wick side distance at 9 cm (5.03 cm) is almost exactly the three-wick worst distance at about 11.6 cm (5.02 cm), a width between the 11 and 12 cm rows. That is the 29.1% scaling in the answer: if two wicks of a given reach just clear the sides of a 9 cm jar, three wicks of the same reach have the geometry for about 11.6 cm. Second, three wicks shrink each wick's share of pool fast: in a 12 cm jar each owns about 37.7 cm², the pool of a single wick in a 6.9 cm jar. That is why a triangle usually runs on a smaller rung than a pair in the same jar.

Reading a two-wick test for the three-wick signal

Nobody needs to design a three-wick candle from theory. Run the two-wick test first, in the jar you intend to sell, with the pair at the quarter points, and watch the two side walls midway between the wicks. What happens there after 3 to 4 hours of the first burn (a candle-maker rule of thumb for a full pool) tells you which way to go.

Two cautions. Soot and a deep pool at the ends can also mean the pair sits too close to the wall; before you jump to three, check the pair really is at the quarter points. And if a single big wick soots in your jar and you have not yet tried a pair, that is a different question with its own fix order: My Large Candle Jar Needs a Huge Single Wick That Produces Soot — Would Two Smaller Wicks Be a Better Choice?. If you are choosing a jar and want to plan one, two or three wicks before committing to production quantities, the planning framework is in I'm Buying a 4-Inch-Wide Luxury Candle Jar — Should I Plan for One Wick, Two Wicks or Three Before Ordering Production Quantities?.

Spacing three wicks, and why not in a line

A triangle is not decoration. Put three wicks in a straight line across a round jar, one in the centre and one either side, and the side walls are still a full D/2 from the middle wick: exactly as far as from a single centred wick. You have added two flames and not shortened the worst distance at all. A line layout suits a long oval or rectangular vessel; in a round jar the three wicks belong at the corners of a triangle.

Making the template

CSI does not list a triangular three-wick holder, so make one. Cut a disc of stiff card a little wider than the rim, draw the inside circle, mark the centre, draw a circle of radius D/4, and mark three points on it 120 degrees apart (step the radius round the circle six times and use every other mark). Punch a hole at each. Stick the three tabs to the jar floor under the holes with wick stickers, thread the wicks through the card and pour. Use the same template for every candle in a test and in production, so the spacing never drifts.

The Steel Wick Holder has three holes, but it is placed across the jar, so its holes sit in a line, and its page gives "up to 9 cm wide". It is a good tool for two wicks in jars up to that width; it is the wrong tool for a triangle. Wick Centering Device bars (₹23.60 each) hold one wick apiece and can hold a pair laid across the rim; three bars for a triangle end up crossing at the rim.

A two vs three test, costed

Worked example in the Clip Top 550 g container, filled to the page's "Wax Fill - 550g" (weigh your own), at 8%: 44 g of oil and 506 g of wax per candle. Candle A: two C1 at the quarter points. B: two C2 at the quarter points. C: three C1 in a triangle at D/4. A fourth candle duplicates the leader, costed here as two C2, the dearest setup. Burn within sight, on a heat-proof surface, never unattended; lid off.

Basket notes. 2,024 g of wax does not fit in two 1 kg bags, so the kit adds a 500 g bag; at ₹0.52 per gram it is 2.5% dearer per gram than the 1 kg, ₹6.30 more on the bag. The oil is tight: two 100 g bottles leave 24 g after four candles, not enough for a fifth. A 500 g bottle is 6.9% cheaper per gram but costs ₹908.60 more up front; buy it only if British Rose, or whichever oil you test with, will be the production scent. The British Rose page states "candles (up to 10% soy, up to 6% paraffin)", so 8% in CSI 464 (up to 10% on its page) sits inside both. If you already own the containers, the kit is ₹2,212.60.

Wick cost is not the deciding factor

Per 100 candles, wicks cost ₹1,180.00 for pairs of C1, ₹1,888.00 for pairs of C2 and ₹1,770.00 for triangles of C1. The triangle is cheaper than the larger pair. What differs more is burn time (three flames usually use wax faster) and heat (three flames put more into the glass). If you print a burn time, measure it on the setup you sell. Costs exclude labour, freight, packaging and GST.

Jars, wicks and holders for the test

The two containers with the largest listed widths in CSI's range, the wick rungs for pairs and triangles, and the accessories that keep three wicks where the template put them. Chosen on what the pages state, price and stock on 26 September 2026; CSI publishes no burn data for any multi-wick setup. The Borosilicate Glass Jar 600 gram (₹200.00, "Ideal for 500–600g wax fill") is another wide candidate, but its page states no dimensions at all, so measure it before planning a layout.

When three wicks are too many

Three flames in a jar that two could pool put more heat into the wax and glass than the job needs. The signs are the narrow-jar signs, multiplied: a deep pool early, tall or merging flames, soot, a fast drop in grams per hour, and glass that is uncomfortable to handle long before the final third. In a small jar the geometry is against you too: in a 7 cm inside diameter, three wicks at D/4 sit 1.75 cm from the wall and about 3 cm from each other, crowded enough that the flames heat one another as much as the wax.

Heat is often the limit in a multi-wick design. Whether two wicks that make the glass much hotter call for a different jar or a different configuration is covered in My Candle Uses Two Wicks and the Glass Gets Much Hotter Than My Single-Wick Candle — Should I Change the Jar or Wick Configuration?; a multi-wick candle that runs too hot only near the end, where the jar shape starts to matter, is covered in My Double-Wick Candle Burns Too Hot Near the End of the Jar — Could the Container Shape Be Contributing to the Problem?. How much pool a wider jar adds, and why the wick follows diameter, is in I'm Using the Same Amount of Wax in a Tall Narrow Jar and a Short Wide Jar — Why Do They Need Different Wick Sizes?.

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