Removal Area Calculator

Inputs

Units:

Removal zones (up to 5)

Each zone adds to the gross area. Quantity multiplies the zone area.

Dimensions are in m unless noted.

Shape	A	B	C	Qty	Help
					Rectangle: A=length, B=width.
					Rectangle: A=length, B=width.
					Rectangle: A=length, B=width.
					Rectangle: A=length, B=width.
					Rectangle: A=length, B=width.

Shapes: Rectangle(A×B), Circle(π·(A/2)²), Triangle(0.5·A·B), Trapezoid(0.5·(A+B)·C), Strip(A×B), Custom(A as area).

Cutouts and exclusions

Subtract doors, shafts, openings, or unremoved areas.

Manual cutouts area (m²)

Use for circular or irregular exclusions you already measured.

Length (m)	Width (m)	Qty	Example: openings, hatches, non-removal patches
			Subtracts (L×W×Qty) from gross area.
			Subtracts (L×W×Qty) from gross area.
			Subtracts (L×W×Qty) from gross area.
			Subtracts (L×W×Qty) from gross area.
			Subtracts (L×W×Qty) from gross area.

Planning factors, productivity, and cost

Optional, but useful for bids and schedules.

Waste / contingency (%)

Typical range: 5–15%. Max allowed: 50%.

Difficulty multiplier

1.0 = normal. Higher = slower (bonded, thick, restricted access).

Productivity (m²/hour per crew)

Your measured output rate for the chosen method.

Crew size (people)

Used to estimate duration from labor hours.

Work hours per day

Shift length excluding breaks, meetings, and travel.

Unit cost (per m²)

Use for coatings, flooring, scarifying, demolition, etc.

Disposal cost (per m²)

Optional: haul-off, tipping, bagging, segregation.

Example data table

Use this as a quick reference for typical entries. Values are illustrative and should be verified for your scope.

Scenario	Zones entered	Cutouts	Waste	Typical use
Floor removal in a room	Rectangle: A=10, B=6, Qty=1	2 openings: 1×0.9	7%	Tiles, epoxy, vinyl, carpet, overlays
Corridor strip	Strip: A=25, B=1.2, Qty=1	Manual cutouts: 1.5 m²	10%	Grinding, shot blasting, membrane removal
Small circular pads	Circle: A=3 (diameter), Qty=2	None	5%	Concrete patch removal, localized demolition

Formula used

Zone area depends on the selected shape:
- Rectangle = A × B
- Circle = π × (A ÷ 2)² (A is diameter)
- Triangle = 0.5 × A × B
- Trapezoid = 0.5 × (A + B) × C
- Strip/Path = A × B (A is path length, B is average width)
- Custom = A (A is a measured area)
Gross area = sum(zone area × quantity)
Cutouts area = sum(cutout length × cutout width × quantity) + manual cutouts area
Net area = max(0, gross area − cutouts area)
Area with waste = net area × (1 + waste% ÷ 100)
Effective productivity = productivity ÷ difficulty multiplier
Labor hours = area with waste ÷ effective productivity
Duration (days) = labor hours ÷ (crew size × hours/day)
Total cost = (area with waste × unit cost) + (area with waste × disposal cost)

This calculator provides planning estimates. Always confirm field measurements, access constraints, and removal method limitations before final pricing.

How to use this calculator

Select your unit system (metric or imperial).
Add one or more zones that represent removal regions.
Pick a shape for each zone and enter its dimensions.
Enter any cutouts to subtract, plus manual exclusions if needed.
Set waste and difficulty to match site conditions.
Enter productivity, crew size, and work hours for scheduling.
Optionally enter unit and disposal costs for budget totals.
Click Calculate to see results above the form.
Use Download CSV or Download PDF for reporting.

Scope definition and measurement strategy

Removal planning starts with a clear scope boundary. Break the work into zones that match how crews will execute: rooms, pads, lanes, or small circular patches. Use the unit system that matches your drawings and field tools, then enter measured dimensions for each zone. When a space is partially removed, model only the affected region to avoid overstating quantities and costs.

Handling irregular rooms and corridors

Not every footprint is a perfect rectangle. For corridors and long runs, the Strip/Path option uses path length and an average width, which is practical for grinding, membrane removal, or scarification along a route. For tapered spaces, the Trapezoid option approximates varying widths without multiple segments. If you already have a measured area from takeoff software, use Custom area to enter it directly.

Cutouts, penetrations, and exclusions

Net removal area should exclude openings, shafts, equipment bases, or protected surfaces. Enter common rectangular cutouts as length and width with quantity, then add any irregular exclusions using the manual cutouts field. This keeps the calculation transparent for reviewers and reduces bid risk when site conditions change. If cutouts exceed gross area, the calculator safely floors net area at zero.

Waste and difficulty adjustments for planning

Waste percent represents edge losses, layout inefficiencies, and rework allowances. Difficulty multiplier reflects access limits, bonded materials, thickness, dust control, or restricted work windows. The calculator applies waste to area and reduces productivity by difficulty, producing a conservative work quantity. Tune these values using historical job data, then document assumptions in the exported report for consistency across projects.

Labor, duration, and cost outputs

Labor hours are computed from area with waste divided by effective productivity. Duration uses crew size and working hours per day to translate labor hours into calendar days. Cost totals combine unit cost and disposal cost multiplied by area with waste, helping compare methods and packaging options. Example data: Rectangle 10×6, Cutouts 2×(1×0.9), Waste 7%, Productivity 25 m²/hr, Difficulty 1.10.

FAQs

1) What does the gross area represent?

Gross area is the sum of all zone areas before subtracting openings or exclusions. It helps you validate takeoff coverage and ensures every removal region is counted once.

2) How should I model an irregular footprint?

Split it into multiple zones, use Trapezoid for tapering widths, or use Strip/Path for long runs with average width. If you already have a measured area, use Custom.

3) When should I use manual cutouts?

Use manual cutouts for irregular exclusions you measured separately, such as circular penetrations, curved openings, or protected areas that are not rectangular.

4) What is the purpose of the waste percentage?

Waste adds a contingency for edge losses, overlaps, layout inefficiency, and minor rework. It increases the planned area so bids and schedules are less likely to run short.

5) How does difficulty affect the result?

Difficulty reduces effective productivity, which increases labor hours and duration. Raise it for restricted access, bonded materials, thicker layers, or heavy dust-control constraints.

6) How do I choose a productivity value?

Use historical output from similar tools and materials. Record the method, crew composition, and constraints. If uncertain, start conservative and refine after a pilot area is completed.

7) What do the CSV and PDF exports include?

Exports include key inputs and the computed summary metrics such as gross, cutouts, net, waste-adjusted area, labor hours, duration, and total cost for sharing and documentation.