Molds are just shapes
Unlike jars, molds usually have straight, regular shapes, which makes them a good fit for geometry. A round pillar or votive is a cylinder: area of the circle times the height. A square or rectangular mold is width times depth times height. A sphere is four thirds of pi times the radius cubed. The calculator works out the volume in milliliters, multiplies by the same 0.86 wax factor used for containers, and splits the result into wax and fragrance.
Always measure the inside of the mold. Metal and polycarbonate molds have thin walls, but silicone molds can be thick, and the outside size can be half an inch bigger all round.
Common pillar sizes
| Pillar (diameter × height) | Finished candle |
|---|---|
| 2 × 3 in | 4.7 oz |
| 3 × 3 in | 10.5 oz |
| 3 × 4 in | 14.1 oz |
| 3 × 6 in | 21.1 oz |
| 3 × 9 in | 31.6 oz |
| 4 × 4 in | 25.0 oz |
| 4 × 6 in | 37.5 oz |
These assume straight sides and a full mold. Candles Molds’ own 3D mold calculator gives the same 463 ml for a 3 × 4 inch cylinder, which is one of the checks we ran. Wax and oil for those sizes depend on your load; set it above.
The second pour
Pillar and votive waxes shrink more than container blends. As the candle cools from the outside in, the center pulls down and leaves a well around the wick. The fix is a second, smaller pour once the first has mostly set. That is why the pour sheet tells you to keep 10 to 15% of your melted wax back. Reheat it a little hotter than your first pour so it bonds, and fill just to the original line.
While the pillar is still soft in the middle, poke a few holes near the wick with a skewer. They let trapped air out and help the second pour fill the hidden gaps, not just the visible dip.
Wicking pillars
A pillar burns differently from a jar: there are no glass walls to hold heat, and ideally the candle burns a pool that leaves a thin outer shell. Wicks for pillars are usually chosen by diameter, and many makers use square braid or cotton core wicks for them. The wick test planner is built around container charts, so for pillars use your supplier’s pillar chart and test a size either side.
Spheres and other shapes
Spheres are popular for decorative candles. The calculator uses the inside diameter. Shapes with ridges, faces or bubbles hold less than their outer size suggests; for those, the water method in the candle wax calculator is the only accurate way.
Questions makers ask
How much wax for a 3 x 4 inch pillar?
A 3 inch wide, 4 inch tall round pillar holds about 463 ml. At 0.86, that is about 14 oz of finished candle. Weigh water in your own mold to confirm, because some molds taper.
Why does my pillar have a sinkhole around the wick?
Pillar waxes shrink as they cool and the center sets last. Poke relief holes near the wick as it sets, then do a second pour with wax a little hotter than the first to fill the hollow. Keep 10–15% of your melted wax for it.
Can I measure a silicone mold with water?
Yes, and it is more accurate than measuring. Seal the wick hole with putty, fill to the line with water, weigh it and multiply by 0.86.
What fragrance load for pillars?
Many pillar waxes are listed lower than container waxes, often around 6%. Too much oil in a free-standing candle can make it soft and sweaty. Check your wax’s spec sheet.
What about tapered or irregular molds?
For anything that is not a straight cylinder, box or sphere, use the water method in the candle wax calculator. It works for any shape.
Sources we checked
- Candles Molds: 3D mold volume calculator
- Candles Molds: water to wax volume converter
- Fillmore Container: wax comparison sheet (June 2024)
Numbers last checked 2026-10-21. How we check them. If your supplier says something different, tell us.