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Concrete Footing Calculator

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Concrete Footing Calculator

Live answer2.17 yd³1.98 yd³ base · 1.66 m³ · 98 bags
Live result2.17 yd³1.98 yd³ base · 1.66 m³ · 98 bags
Formula used

Width feet = footing width inches ÷ 12. Depth feet = footing depth inches ÷ 12. Base cubic feet = length feet × width feet × depth feet × number of footings. Cubic yards = cubic feet ÷ 27. Order volume = base volume × (1 + waste percent ÷ 100). Cubic metres = cubic yards × 0.764554857984. Bags = ceiling(order cubic feet ÷ bag yield cubic feet).

This is the method behind the answer, so the result can be checked rather than simply trusted.

Live math canvas

Your numbers, formula and explanation together

Concrete Footing Calculator: 2.17 yd³. 1.98 yd³ base · 1.66 m³ · 98 bags

Formula applied

The exact method behind this answer

CalculationTime keeps the method visible so the number can be checked instead of blindly trusted.

Width feet = footing width inches ÷ 12. Depth feet = footing depth inches ÷ 12. Base cubic feet = length feet × width feet × depth feet × number of footings. Cubic yards = cubic feet ÷ 27. Order volume = base volume × (1 + waste percent ÷ 100). Cubic metres = cubic yards × 0.764554857984. Bags = ceiling(order cubic feet ÷ bag yield cubic feet).
  1. Apply the formulaWidth feet = footing width inches ÷ 12. Depth feet = footing depth inches ÷ 12. Base cubic feet = length feet × width feet × depth feet × number of footings. Cubic yards = cubic feet ÷ 27. Order volume = base volume × (1 + waste percent ÷ 100). Cubic metres = cubic yards × 0.764554857984. Bags = ceiling(order cubic feet ÷ bag yield cubic feet).2.17 yd³1.98 yd³ base · 1.66 m³ · 98 bags

Your live breakdown

Current inputs in the calculation

These values come from the controls above and update when the calculator changes.

Footing length
40 ft
Enter total continuous footing length in feet. Add separate runs together before entering.
Footing width
16 in
Enter the planned footing width in inches.
Footing depth
12 in
Enter the concrete depth or thickness in inches.
Number of matching footings
1
Use this when several footing runs share the same length, width and depth.
Waste / overdig allowance
10 %
Add allowance for over-excavation, spillage, uneven trench bottoms and ordering margin.
Bag yield
0.6 ft³/bag
Use the yield printed on the bag if estimating bagged concrete.

Resulting answer

2.17 yd³

1.98 yd³ base · 1.66 m³ · 98 bags

Answer
2.17 yd³
Live support
1.98 yd³ base · 1.66 m³ · 98 bags

Assumptions used

What this answer assumes

Best for strip footings, garden wall footings, shed footings, small foundation estimates, quote notes and construction math worksheets where the size and waste allowance need to stay auditable.

  • The calculator treats each footing as a straight rectangular prism; stepped, haunched, belled or irregular excavations need separate checks.
  • Width and depth are entered in inches and converted to feet before volume is calculated.
  • The allowance is shown separately so overdig, spillage and ordering margin do not hide the measured concrete requirement.
  • Bag count is rounded up to whole bags using the entered bag yield; actual bag yield depends on product, water addition and site practice.
  • This calculator is for quantity estimating only. Footing size, reinforcement, soil capacity, frost depth, inspection and code compliance must be confirmed by qualified local authority or professionals.

Master’s Tip

How to use the result well

Master’s Tip: print the footing dimensions before ordering concrete and keep structural design separate from quantity takeoff. A trench that is only two inches wider than planned can materially change the order on a long run.

Printable record

What belongs in the saved calculation

Save the inputs, result, formula, assumptions, page URL and date together so the calculation can be reviewed later.

Footing length
40 ft
Enter total continuous footing length in feet. Add separate runs together before entering.
Footing width
16 in
Enter the planned footing width in inches.
Footing depth
12 in
Enter the concrete depth or thickness in inches.
Number of matching footings
1
Use this when several footing runs share the same length, width and depth.

Visual grid

This result measures part of the space you live in

Length, area, volume and material estimates are grid problems too: measure the space, account for edges and allowances, then turn the pattern into a number you can use.

Micro-timehours, minutes, shiftsHuman scaledays, weeks, projectsMacro-timemonths, years, calendars
Measured output2.17 yd³

Space calculations turn a real surface, room, run or volume into cells, edges and allowances that can be quoted, ordered or checked.

CalculationTime

Concrete Footing Calculation Report

Report date:

2.17 yd³1.98 yd³ base · 1.66 m³ · 98 bags

Inputs

Footing length
40 ft
Footing width
16 in
Footing depth
12 in
Number of matching footings
1
Waste / overdig allowance
10 %
Bag yield
0.6 ft³/bag

Method

Width feet = footing width inches ÷ 12. Depth feet = footing depth inches ÷ 12. Base cubic feet = length feet × width feet × depth feet × number of footings. Cubic yards = cubic feet ÷ 27. Order volume = base volume × (1 + waste percent ÷ 100). Cubic metres = cubic yards × 0.764554857984. Bags = ceiling(order cubic feet ÷ bag yield cubic feet).

  1. For one 40 ft footing that is 16 in wide and 12 in deep, width = 16 ÷ 12 = 1.333 ft and depth = 1 ft. Base volume = 40 × 1.333 × 1 × 1 = 53.33 ft³, or 1.98 yd³. With a 10% allowance, order about 2.17 yd³.

Assumptions

  • The calculator treats each footing as a straight rectangular prism; stepped, haunched, belled or irregular excavations need separate checks.
  • Width and depth are entered in inches and converted to feet before volume is calculated.
  • The allowance is shown separately so overdig, spillage and ordering margin do not hide the measured concrete requirement.
  • Bag count is rounded up to whole bags using the entered bag yield; actual bag yield depends on product, water addition and site practice.

Notes

Use this space on the printed report for client, supplier, classroom, job-location, measurement, quote or approval notes.

Source: https://www.calculationtime.com/calculators/concrete-footing-calculator

This report shows the calculation inputs, formula, assumptions and result for review. It is not legal, payroll, tax, engineering, financial or academic advice unless a qualified professional confirms the applicable rules.