Skip to main content
CalcChef

Candle Burn Time & Wax Fragrance Calculator

Wax weight and fragrance oil for a candle jar from its inside diameter, fill height, wax and load, plus a rough burn time from fixed burn rates. How it works

Use the Candle Burn Time & Wax Fragrance Calculator

Weigh the wax you pour. When filled, it replaces the weight worked out from the container size.

Unit system
Estimated Total Burn Time
173.2 hrs

Breakdown

Wax to Fill the Container14.71 oz
Fragrance Oil (added to the wax)0.883 oz
Burn Rate0.090 oz/hr

From fixed burn rates, not a measurement. Real candles often burn faster, so time a test burn of your own candle.

About the Candle Burn Time & Wax Fragrance Calculator

A jar 3 inches across, filled 4 inches deep, holds 14.71 oz of soy wax. At a 6% fragrance load it takes 0.883 oz of fragrance oil, and with a medium wick this candle burn time calculator estimates 173.2 hours at 0.090 oz an hour. The wax weight follows from the jar's volume and the wax density; the burn rate is the tool's own fixed figure, not a measurement, and real candles often burn faster.

How to use this tool

  1. Choose Imperial or Metric, then type the container's inside diameter and the height you will fill with wax.
  2. Pick the wax (soy, paraffin, beeswax or coconut), the fragrance load in percent and the wick size.
  3. If you weighed the wax, type it as the measured wax weight: it replaces the weight worked out from the container.
  4. Read the burn time, the wax, the fragrance oil to add and the burn rate.

Frequently asked questions

How much wax do I need to fill a candle jar?
Multiply the jar's inside volume by the wax density and by 0.578 oz, the weight of one cubic inch of water. A 3-inch-wide jar filled 4 inches deep holds 14.71 oz of soy wax. In metric mode, type centimetres and the wax is given in grams.
How much fragrance oil do I add to candle wax?
Wax weight times the fragrance load: 6% of 14.71 oz of wax is 0.883 oz of oil. The tool warns above a 10% load.
Does fragrance oil replace some of the wax?
Not in this tool. The oil is added on top of the wax that fills the jar, so wax plus oil overfills it by roughly the fragrance load. To fill to the same height, reduce the wax by that share.
Does wick size change the burn time?
Yes. A small wick lowers the burn rate and lengthens the estimate, and a large wick raises the rate and shortens it. The tool also warns above a 10-inch (25.4 cm) diameter, where a larger wick helps stop the candle tunnelling.
How do I find my candle's real burn rate?
Weigh the candle, burn it for a few hours, weigh it again and divide the weight lost by the hours burned. The tool's burn rates do not change with the jar's diameter, draft or fragrance, so a test burn of your own candle is the better figure.
Can I enter the wax I actually weighed?
Yes. Type it as the measured wax weight, in oz, or in grams in metric mode, and it replaces the weight from the container size. 10 oz of soy wax at 6% takes 0.6 oz of fragrance oil and gives 117.8 hours with a medium wick; 300 g takes 18 g of oil and gives 124.6 hours.

Estimating burn time before you pour

A 3 × 4 inch soy candle at 6% fragrance with a medium wick comes to 14.71 oz of wax, 0.883 oz of fragrance oil and 173.2 hours at 0.090 oz per hour.

If you weigh the wax you pour, type it as the measured wax weight and it replaces the container estimate: 10 oz of soy at 6% takes 0.6 oz of oil and gives 117.8 hours, and 300 g takes 18 g of oil and gives 124.6 hours.

The fragrance is added on top of the wax, so the mix overfills the jar by roughly the load. To fill to the same height, divide the wax by 1.06 at 6% (14.71 ÷ 1.06 ≈ 13.88 oz, with 0.83 oz of oil). In metric mode an 8 × 10 cm soy candle at 6% shows 452.4 g of wax and 187.9 hours.

The burn-time formula

volume = π × (diameter ÷ 2)² × height in cubic inches (centimetres ÷ 2.54 first)

wax oz = volume × density × 0.578, or your measured weight; fragrance = wax × load ÷ 100

hours = (wax + fragrance) ÷ (base rate ÷ wick factor)

Densities are 0.86 for paraffin, 0.90 soy, 0.92 coconut and 0.96 beeswax, relative to water; 0.578 oz is the weight of one cubic inch of water. Base burn rates are 0.07, 0.09, 0.10 and 0.08 oz per hour in the same order, and the wick factor is 1.2 for small, 1.0 medium and 0.85 large.

The burn rates and wick factors are this tool's own fixed figures, not from a published source, and they do not change with the diameter. They are low next to what candle makers measure: one UK candle supplier's test burn lost 4 g of wax an hour (about 0.14 oz), against 0.09 oz (about 2.6 g) for soy here, so the hours shown are likely too high. Tunnelling and wick trimming are ignored.

Related Tools

View all tools
Maker

3D Print Cost Calculator

3D print cost from model weight, filament price per kg, print time, printer watts and electricity rate, plus an optional waste allowance, wear and labor.

Maker

Gear Ratio Calculator

Gear ratio, output RPM and speed change for one pair of gears or sprockets, from the driver and driven tooth counts and the input RPM.

Maker

Thread Yardage Estimator

Estimate sewing thread in yards and 500-yard spools for a garment, jacket, quilt, pillow, bag or hem from seams, stitch type and thread weight.