Close this search box.

Etched-foil heaters have gained significant popularity due to their flexibility, uniform heat distribution, and rapid response times. These heaters consist of a resistive heating element etched onto a thin foil substrate, providing excellent thermal conductivity. Accurate estimation of power requirements is essential for designing the electrical circuitry and ensuring optimal performance of the heating system.

This calculator models the conduction, radiation, and convection losses of a heat sink, as well as process heat requirements, to assist you in determining heater wattage needs.  Add input values in the appropriate fields below and the calculator will provide an estimate the minimum heater wattage.  See the “Minco Heater Wattage Estimator” video for further instruction.

For more detail on estimating heater wattage, see our corresponding white paper, “Estimating Power Requirements of Etched-Foil Heaters“.


Thermal System Example

Diagram showing heater operating requirements

We will estimate the steady-state operating requirements and the warm-up requirements. The estimated minimum wattage required will be the greater of the two sets of requirements, plus a small buffer.



Conductive Losses

When speaking of etched-foil heaters, conductive loss generally refers to loss through insulation layers or heat sink mounting hardware. The conductive loss also depends upon the ambient temperature.

Radiation Losses

Radiation is heat emitted as infrared energy. The radiation losses also depend on the ambient temperature and the final temperature of the heat sink.

Natural Convection Losses

Natural convection occurs when heated air rises and creates air currents. The natural convection losses also depend on the ambient temperature and the final temperature of the heat sink.

Forced Air Convection Losses

Forced air convection occurs when fans or wind drive air past the heater. The forced air convection losses also depend on the ambient temperature and the final temperature of the heat sink.

Warm-up Heat

Warm-up heat is the heat required to bring the heat sink to temperature in the desired time, plus heat to compensate for conductive, radiant, and convective losses during warm-up.

Process Heat Requirements

Process heat represents work done by the heater to thermally process some material. Examples of process heat are melting a plastic film placed over a heat sink or heating a PCB to a set temperature.

If processed material changes state:


After comparing the warm-up heat and the operating heat, we estimate the minimum heater wattage.

To reach this estimate, we calculate the operating heat.

Overridden Value?

We compare the operating heat to the warm-up heat.

We add 10% buffer to the greater of the two in order to estimate the minimum heater wattage.


For more than 60 years, Minco has designed and manufactured heating, flex circuit, temperature sensing and instrumentation solutions for some of the world’s most demanding applications.


Address a specific design challenge or customize fully integrated solutions with Minco’s proven product lines.

Thermal performance for standard and custom use cases — from environment stabilization to faster thermal cycling.

Accurately sense and measure temperature, humidity and fluid levels across a wide range of applications.

Achieve new design freedom with flex circuit solutions that improve reliability in a condensed package size.

System-matched controllers complement Minco sensors and heaters to deliver improved system accuracy.

Leverage decades of engineering expertise to design integrated solutions that enhance performance and reduce cost.
Learn more about Minco’s approach to design innovation – and consider joining the team.