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Efficiency Ratio Of Floor Plate Calculator

Work out efficiency ratio of floor plate instantly with clear inputs, formula shown and shareable results.

About Efficiency Ratio Of Floor Plate Calculator

Floor plate efficiency is net usable area as a share of gross, after removing the core of lifts, stairs, risers and toilets, plus primary circulation. Efficient office plates achieve 80-85 percent; anything below 75 percent means tenants are paying for a lot of space they cannot occupy.

Formula

Efficiency

Efficiency = (gross - core - circulation) / gross x 100

Worked example

With the default values below, Efficiency Ratio Of Floor Plate Calculator returns Floor plate efficiency of 75.00%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Gross floor areaminimum 0.1 m²
2,000 m²
Core areaminimum 0 m²
320 m²
Circulation areaminimum 0 m²
180 m²

Results

Floor plate efficiency
75.00% %
Net usable area
1,500.0 m²
Core as share of gross
16.00% %
Area lost to core and circulation
500.0 m²

Step by step

  1. 1Values used
  2. 2Efficiency
  3. 3Floor plate efficiency= 75.00 %
  4. 4Net usable area= 1,500.0 m²
  5. 5Core as share of gross= 16.00 %
  6. 6Area lost to core and circulation= 500.0 m²

Assumptions and limits

  • The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Efficiency Ratio Of Floor Plate figure worked out?

Efficiency = (gross - core - circulation) / gross x 100. Floor plate efficiency is net usable area as a share of gross, after removing the core of lifts, stairs, risers and toilets, plus primary circulation.

What drives poor efficiency?

A deep core relative to a small floor plate, awkward geometry, and multiple stair cores driven by escape distances. Tall towers with small floors are structurally forced into low efficiency.

What values do I need to enter?

This calculator takes 3 inputs: Gross floor area, Core area, Circulation area. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.

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