Work out furnace melting energy instantly with clear inputs, formula shown and shareable results.
Melting energy has two parts: sensible heat to raise the charge to melting and then to pouring temperature, m x c x ΔT, and latent heat of fusion to change state, m x L. Steel needs roughly 0.4 kWh per kilogram theoretically; real furnaces use 1.5 to 2 times that because of radiation, wall and off-gas losses.
Melting energy
kJ = mass x (specific heat x ΔT + latent heat of fusion)
Power rating
kW = kWh / melt hours
kJ = mass x (specific heat x ΔT + latent heat of fusion). Melting energy has two parts: sensible heat to raise the charge to melting and then to pouring temperature, m x c x ΔT, and latent heat of fusion to change state, m x L.
Furnace shell losses, door openings, electrode or burner inefficiency and holding time all add energy that never reaches the metal. Induction furnaces are closest to theoretical, cupolas the furthest.
This calculator takes 4 inputs: Charge mass, Specific heat capacity, Temperature rise to pouring, Latent heat of fusion. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.