Cost Estimation Based on Area with Unit Rate Examples
Cost Estimation Based on Area calculates the total expense for flooring, painting, carpeting, tiling, fencing, or construction when the area and rate per unit area are given. Solve these questions by finding the correct area, converting units when required, and multiplying the area by the applicable rate.
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What is Cost Estimation Based on Area?
For a region with area A and rate R, total cost is C = A × R. If different parts have different rates, calculate each part separately and add the costs. For example, flooring 40 m² at ₹250 per m² costs 40 × 250 = ₹10,000.
Cost Estimation Based on Area Video Lessons
Watch short topic-wise lessons for quick revision.
Cost Estimation in Mensuration
Learn how to calculate the cost of areas and boundaries in two-dimensional mensuration using given measurements and applicable rates.
Cost Estimation Based on Area Formula & Tricks
Important Formulas
Use the area in the same unit as the rate, such as m² with ₹ per m².
Use this when the total expenditure and rate are known.
The resulting unit is currency per square unit, such as ₹/m².
Use this formula for rectangular floors, fields, walls, and plots.
All four sides of a square are equal.
Here r is the radius. Use the value of π specified in the question, usually 22/7 or 3.14.
Quick Tricks
The area unit must match the rate unit. Remember 1 m² = 10,000 cm² and 1 hectare = 10,000 m².
For a path outside a rectangle, subtract the inner area from the outer area. For a path around a circle, subtract the inner circular area from the outer circular area.
Do not apply one rate to the whole region when parts have different materials or prices.
Cost Estimation Based on Area Concepts
Cost of flooring a rectangular or square region
For a rectangle, cost = length × breadth × rate. For a square, cost = side² × rate. Length and breadth must be measured in the same unit.
Painting cost for walls
For four walls of a rectangular room, area of four walls = 2h(l + b), where l is length, b is breadth, and h is height. Net painted area = wall area − area of doors and windows. Total cost = net painted area × painting rate.
Cost of paths and borders
For a rectangular path, path area = outer length × outer breadth − inner length × inner breadth. For a square border, path area = outer side² − inner side². Multiply the resulting area by the rate.
Different rates for different regions
If areas A₁ and A₂ have rates R₁ and R₂, total cost = A₁R₁ + A₂R₂. This method applies to combined flooring, painting, paving, and tiling problems.
Cost Estimation Based on Area Visual Guide & Data
Use the table and chart below to understand the data better.
Common area-unit conversions
Conversions frequently used in cost estimation problems
| Given unit | Equivalent value |
|---|---|
| 1 m² | 10,000 cm² |
| 1 m² | 1,000,000 mm² |
| 1 hectare | 10,000 m² |
| 1 km² | 1,000,000 m² |
Note: Convert the area, not only the length, because area units are squared.
Worked cost calculation
Separate calculation for two regions with different rates
| Region | Area | Rate | Cost |
|---|---|---|---|
| Flooring | 40 m² | ₹250/m² | ₹10,000 |
| Carpeting | 20 m² | ₹150/m² | ₹3,000 |
| Total | 60 m² | Different rates | ₹13,000 |
Note: The total cost is the sum of the individual costs, not total area multiplied by one rate.
Rectangular region used for cost estimation
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Cost Estimation Based on Area: Revision Points
Use these formulas and rules for quick revision.
- Total cost = Area × rate per unit area.
- Rectangle area = length × breadth; square area = side².
- Four-wall area of a room = 2h(l + b).
- Net painted area = total area − doors and windows area.
- Path or border area = outer area − inner area.
- For different rates, total cost = A₁R₁ + A₂R₂ + ...
- 1 m² = 10,000 cm²; 1 hectare = 10,000 m².
- Match the area unit with the rate unit before calculating.
Cost Estimation Based on Area FAQs
What is the cost estimation based on area formula?
Total Cost = Area × Rate per unit area. For example, 25 m² at ₹80 per m² costs 25 × 80 = ₹2,000.
How is the cost of a rectangular floor calculated?
Calculate area as length × breadth and multiply by the rate. A 10 m × 6 m floor at ₹200 per m² costs 10 × 6 × 200 = ₹12,000.
How do you calculate the cost of a path around a rectangle?
Subtract the inner rectangle's area from the outer rectangle's area, then multiply by the path rate. Thus, path cost = (outer area − inner area) × rate.
What is the area of four walls of a rectangular room?
The area is 2h(l + b), where l is length, b is breadth, and h is height. The areas of doors and windows must be subtracted if they are not painted.
How do you handle two materials with different rates?
Find each material's area and multiply it by its own rate. Add the results: total cost = A₁R₁ + A₂R₂.
How many square metres are in one hectare?
1 hectare = 10,000 m². Therefore, land measuring 2.5 hectares has an area of 25,000 m².