Is this percentage of the whole vessel?

No. It is percentage of the entered rated working capacity. Brimful capacity can be larger and would produce a different percentage.

What minimum fill should I enter?

Use the manufacturer and process-qualified limit for your mixer and material. Required agitator contact varies with geometry; no single percentage fits all mixers.

Why can the headroom be negative?

The charge exceeds your entered maximum operating volume. Reduce the charge or qualify a different operating window before using that plan.

Can a batch fit but still overload the mixer?

Yes. Material density and behavior affect mechanical loading. Check the applicable drive and shaft limits separately from volume occupancy.

Mixing, Blending & Industrial Batch Processing calculator

Mixer Fill Percentage Calculator

Calculate how much rated working capacity your charge occupies. Enter charge volume, working capacity, and the qualified minimum and maximum fill percentages for this mixer and recipe.

What this calculator does

Compare planned charge volume with rated working capacity and your qualified operating fill window.

Formula used

Working-volume fill = charge volume ÷ working capacity × 100
Minimum batch volume = working capacity × minimum fill ÷ 100
Maximum batch volume = working capacity × maximum fill ÷ 100
Headroom = maximum batch volume − charge volume

Inputs explained

Planned Charge Volume: Material volume after charging, before foam or process expansion.
Rated Working Capacity: Manufacturer-approved working capacity, not the vessel brimful volume.
Minimum Working-Volume Fill: Qualified minimum as a percentage of the entered working capacity.
Maximum Working-Volume Fill: Qualified maximum as a percentage of the entered working capacity.

How to use the result

Best suited to batch charge planning, partial-batch operating review.
Fill percentage does not check torque, bulk density, or mixing uniformity. Foaming, thermal expansion, and transient volume changes require separate allowance.

Common questions

Is this percentage of the whole vessel? No. It is percentage of the entered rated working capacity. Brimful capacity can be larger and would produce a different percentage.
What minimum fill should I enter? Use the manufacturer and process-qualified limit for your mixer and material. Required agitator contact varies with geometry; no single percentage fits all mixers.
Why can the headroom be negative? The charge exceeds your entered maximum operating volume. Reduce the charge or qualify a different operating window before using that plan.
Can a batch fit but still overload the mixer? Yes. Material density and behavior affect mechanical loading. Check the applicable drive and shaft limits separately from volume occupancy.

Last reviewed 2026-10-01.