Glass Fusing Schedule Calculator

Kiln firing schedule from glass type and project.

Total thickness (mm)

Fusing type

COE type

Kiln width (inches)

Digital controller

Tab to move between fields

Top temperature (°C)

800

Anneal soak (min)30

Slow cool rate (°C/min)1.5

Anneal cool duration (min)23

Annealing point (°C)510

Strain point (°C)475

Total schedule (min)431

Total schedule (hours)7.2

Est. energy (kWh)22.3

How to Use This Calculator

Enter the Total Thickness of the layup in mm and select the Fusing Type: tack fuse, full fuse, or slump.
Select the COE type (COE 90 for Bullseye, COE 96 for Spectrum) and enter your Kiln Width.
Indicate whether you have a Digital Controller for precise ramp and hold programming.
Review Top Temperature, Anneal Soak time, Slow Cool Rate, and Annealing Zone Duration.
Check Total Schedule Hours and Estimated Energy to plan kiln scheduling and electricity costs.

What each input means

Total thickness (mm): Total layup thickness after fusing. 2 layers of 3mm = 6mm.
Fusing type: 0 = Tack fuse (~730°C), 1 = Full fuse (~800°C), 2 = Slump (~650°C).
COE type: 0 = COE 90 (Bullseye/Uroboros), 1 = COE 96 (Spectrum/System 96).
Kiln width (inches): Interior width of your kiln for energy estimation.
Digital controller: 1 = Digital kiln controller, 0 = Manual (adds safety margin).

Top temperature (°C): Peak firing temperature for the selected fusing type.
Anneal soak (min): Hold time at annealing point. Longer for thicker glass.
Slow cool rate (°C/min): Maximum cooling rate through the critical annealing zone.
Anneal cool duration (min): Time to cool through the annealing zone (annealing → strain point).
Annealing point (°C): Temperature at which internal stresses begin to relax.
Strain point (°C): Below this temp, glass is rigid and stresses are locked in.
Total schedule (min): Estimated total firing schedule time.
Total schedule (hours): Total schedule in hours.
Est. energy (kWh): Rough energy consumption estimate.

Identify Input Parameters
4 parameters
Total thickness (mm) = 6, Fusing type = 1, COE type = 0, Kiln width (inches) = 18 = 5 input(s) provided
Calculate Top temperature
800 = 800
Calculate Anneal soak
Anneal soak = round(30 * thicknessFactor)
30 = 30
Calculate Slow cool rate
Slow cool rate = baseCoolRate / thicknessFactor
1.5 = 1.5