Dryer Load Calculator

Related tools: Appliance Load Calculator, Residential Load Calculator, and Commercial Load Calculator.

A dryer load calculator converts multiple dryer nameplate ratings into the electrical load used for preliminary branch-circuit or feeder planning. It produces three practical values: Connected dryer load, Demand dryer load, and Dryer current.

The demand current is the value commonly carried into an early load review and then evaluated against conductor ampacity, overcurrent protection, raceway fill, feeder layout, available panel capacity, and voltage-drop conditions. The calculation begins with the dryers’ combined nameplate kW, applies the selected demand factor, and converts the resulting VA load to amperes at the selected system voltage and phase.

This workflow requires a known dryer nameplate load and an established demand-factor basis. It does not determine whether a demand factor is permitted for a particular installation.

Dryer Load Inputs

Field	Electrical purpose
Dryer nameplate load	The rated load of one dryer, entered in kW. Use the electrical nameplate value rather than an estimated heating-element size or connected gas load.
Dryer count	The number of dryers included in the load calculation.
Demand factor	The percentage applied to the connected dryer load for the demand-load result.
System voltage	The circuit voltage used to convert demand VA into current.
Phase	Selects single-phase or balanced three-phase current math.

The Dryer nameplate load and Dryer count establish the total connected dryer load. The Demand factor reduces that connected load only for the demand calculation entered on this screen. System voltage and Phase then determine the displayed current.

Connected and Demand Dryer Load

The calculator first calculates the total connected dryer load:

\(\displaystyle \text{Connected dryer load (VA)} = \text{Dryer nameplate load (kW)} \times 1{,}000 \times \text{Dryer count}\)

It then applies the entered demand factor:

\(\displaystyle \text{Demand dryer load (VA)} = \text{Connected dryer load (VA)} \times \frac{\text{Demand factor (\%)}}{100}\)

The connected load represents all listed dryers operating at their combined nameplate rating. The demand load is the portion of that connected load carried forward after applying the selected demand percentage.

For a laundry area, multifamily installation, or commercial equipment schedule, the connected value is useful for documenting the installed equipment total. The demand value is the load used for the calculator’s current conversion.

Dryer Current Calculation

The calculator converts Demand dryer load from VA to amperes using the selected voltage and phase.

For Single-phase systems:

\(\displaystyle \text{Dryer current (A)} = \frac{\text{Demand dryer load (VA)}}{\text{System voltage (V)} \times 1}\)

For balanced Three-phase systems:

\(\displaystyle \text{Dryer current (A)} = \frac{\text{Demand dryer load (VA)}}{\text{System voltage (V)} \times \sqrt{3}}\)

The displayed Phase multiplier identifies the current-conversion divisor:

Phase selection	Phase multiplier
Single-phase	1 x
Balanced three-phase	\(\sqrt{3}\) x

A three-phase result assumes the dryer load is balanced across the phase conductors. An unbalanced appliance arrangement requires conductor-by-conductor review rather than relying solely on a balanced three-phase current result.

Calculation Example

Use the following values:

Input	Value
Dryer nameplate load	5 kW
Dryer count	3
Demand factor	75%
System voltage	240 V
Phase	Single-phase

Connected dryer load

\(\displaystyle 5\text{ kW} \times 1{,}000 \times 3 = 15{,}000\text{ VA}\)

Connected dryer load: 15,000 VA

Demand dryer load

\(\displaystyle 15{,}000\text{ VA} \times 75\% = 11{,}250\text{ VA}\)

Demand dryer load: 11,250 VA

Dryer current

\(\displaystyle \frac{11{,}250\text{ VA}}{240\text{ V} \times 1} = 46.875\text{ A}\)

Dryer current: 46.875 A

This 46.875 A value can be used as the starting current for preliminary feeder conductor and raceway planning. Final conductor selection still requires the applicable ampacity basis, conductor material, AWG or kcmil size, insulation temperature rating, terminal rating, ambient-temperature correction factor, adjustment factor for current-carrying conductors, and installation conditions.

Field Verification

Verify each dryer’s electrical nameplate before using the result for design or installation decisions. A dryer may have manufacturer instructions, branch-circuit requirements, voltage-specific ratings, motor loads, control loads, or other characteristics that are not represented by a single generalized demand calculation.

The calculator applies the entered Demand factor arithmetically; it does not establish the code basis for that percentage. Confirm the selected demand treatment with the applicable electrical requirements, project documents, utility or service-load criteria where applicable, and the AHJ.

The displayed Dryer current is not by itself a final conductor, breaker, or disconnecting-means selection. Final work must account for the actual circuit arrangement, equipment listing and instructions, terminal ratings, ampacity limitations, overcurrent protection, voltage drop, conductor routing, raceway fill, and whether the load is single-phase or balanced across a three-phase system.