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Kiln Loading Calculator — Shelf Usage & Firing Cost

Calculate how many pieces fit in your kiln, plan shelf usage and estimate electricity cost per firing.

Round kilns use diameter, square use width and depth

Affects firing time and loading rules

Internal width or diameter of your kiln

Internal height of the kiln chamber

How many shelves you plan to use

Average width of your pieces

Average depth (front to back) of your pieces

How We Calculate This

This calculator estimates how many ceramic pieces fit on each kiln shelf based on piece footprint and usable shelf area, then calculates total capacity and electricity cost.

Formulas

  • Usable area = Shelf area minus 2cm edge clearance all round
  • Pieces per shelf = Usable area ÷ (piece width + spacing) × (piece depth + spacing)
  • Electricity cost = Kiln kW × Firing hours × Price per kWh
  • Cost per piece = Total electricity cost ÷ Number of pieces

Frequently Asked Questions

Last updated: March 2026

All calculations are estimates. Always verify quantities before purchasing materials.