How do you calculate ladle preheat energy cost?

Multiply the preheater's connected load (kW) by the runtime (hours) by your blended energy rate ($/kWh). At 85 kW for 5 hours at $0.12/kWh that is 425 kWh, or $51 per cycle.

What is the cost per heat for preheating a ladle?

Divide total cycle cost by the number of heats that cycle supports. In the worked example, $51 spread across 6 heats is $8.50 per heat.

Why is my ladle preheat energy higher than expected?

The usual culprits are excessive runtime (preheating well past the refractory's required soak), an undersized lid letting heat escape, or a high blended rate during peak demand windows. Logging actual burner-on minutes versus scheduled minutes usually exposes the gap.

Is electric or gas ladle preheating cheaper?

It depends entirely on your local blended rate. This calculator normalizes everything to $/kWh so you can compare a 85 kW electric resistance unit against the kWh-equivalent of a gas burner on the same footing.

How much does runtime affect the cost?

Cost is linear with runtime. Cutting the 5-hour runtime to 4 hours drops energy from 425 kWh to 340 kWh and cost from $51 to about $40.80 per cycle, roughly $1.70 saved per heat at 6 heats.

What is a good ladle preheat cost per heat?

There is no universal benchmark, but in iron and steel foundries running covered, regenerative preheaters, $5-$10 per heat is common; the $8.50 in this example sits in a normal range and the lever to lower it is shorter, better-insulated soak cycles.

Foundry & Forging calculator

Ladle Preheat Energy Calculator

Ladle preheating is one of the quietest energy line items in a foundry or steel shop, yet a single 85 kW preheater running between heats can burn through real money before a drop of metal is poured. This calculator turns preheater load, runtime and your blended energy rate into a hard dollar figure and, more usefully, a cost-per-heat number. Melt supervisors, energy managers and cost estimators use it to decide whether ladles are sitting on burners longer than refractory life or pour temperature actually requires. When you preheat a dozen ladles a shift, trimming even 30 minutes off each cycle compounds fast.

What this calculator does

Estimate energy cost for ladle preheating before tapping, transfer, or pouring.
Use it when ladle preheat time, burner/electric load, and energy rate affect heat cost or metal temperature control.
It computes the total energy cost of a ladle preheat cycle (load x runtime x rate) and divides it across the heats or ladles that cycle supports.

Formula used

Total ladle preheat energy = ladle preheater load × ladle preheat runtime × blended energy rate
Ladle Preheat Energy cost per processed unit = total energy cost ÷ heats or ladles supported

Inputs explained

Ladle preheater connected load:
Preheat burner runtime per cycle:
Blended gas-and-electric energy rate:
Heats poured per preheat cycle:

How to use the result

Use it when sizing preheat schedules, building a cost-per-ton energy model, or justifying a switch to a higher-efficiency or regenerative ladle preheater.
It assumes the preheater draws at full connected load for the entire runtime; modulating or thermostatically cycled burners draw less on average, so treat the result as a worst-case ceiling unless you use a measured average load.

Current U.S. benchmarks

As of Apr 2026, industrial electricity averages 8.7 cents per kWh across the U.S. (EIA), up 5.5% from a year earlier. State averages range widely, so plants should confirm against their own tariff.
The producer price index for steel mill products stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The U.S. has 3,569 primary metal manufacturing establishments employing about 354,911 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate ladle preheat energy cost? Multiply the preheater's connected load (kW) by the runtime (hours) by your blended energy rate ($/kWh). At 85 kW for 5 hours at $0.12/kWh that is 425 kWh, or $51 per cycle.
What is the cost per heat for preheating a ladle? Divide total cycle cost by the number of heats that cycle supports. In the worked example, $51 spread across 6 heats is $8.50 per heat.
Why is my ladle preheat energy higher than expected? The usual culprits are excessive runtime (preheating well past the refractory's required soak), an undersized lid letting heat escape, or a high blended rate during peak demand windows. Logging actual burner-on minutes versus scheduled minutes usually exposes the gap.
Is electric or gas ladle preheating cheaper? It depends entirely on your local blended rate. This calculator normalizes everything to $/kWh so you can compare a 85 kW electric resistance unit against the kWh-equivalent of a gas burner on the same footing.
How much does runtime affect the cost? Cost is linear with runtime. Cutting the 5-hour runtime to 4 hours drops energy from 425 kWh to 340 kWh and cost from $51 to about $40.80 per cycle, roughly $1.70 saved per heat at 6 heats.

Last reviewed 2026-05-12.