Footing Quantity Inputs
Use total measured footing lengths from the plan. Use one consistent footing size per calculation. Recalculate separate footing types as separate takeoffs.
Example Data Table
| Item | Example Input | Purpose |
|---|---|---|
| Continuous footing | 160 ft × 16 in × 8 in | Exterior and interior bearing-wall footing volume. |
| Pad footings | 4 pads × 3 ft × 3 ft × 12 in | Post or concentrated-load footing volume. |
| Concrete waste | 7% | Planning allowance added to the designed concrete quantity. |
| Excavation clearance | 6 in sides and 3 in bottom | Working room and cleanup estimate for earthwork planning. |
| Longitudinal rebar | 2 runs with 10% lap allowance | Simple continuous-footing rebar takeoff. |
Formula Used
- Continuous footing concrete
- Length (ft) × [Width (in) ÷ 12] × [Depth (in) ÷ 12] = cubic feet.
- Pad footing concrete
- Pad count × Length (ft) × Width (ft) × [Thickness (in) ÷ 12] = cubic feet.
- Concrete order quantity
- (Continuous concrete + Pad concrete) × [1 + Waste percentage ÷ 100]. Divide cubic feet by 27 for cubic yards.
- Excavation estimate
- Expanded trench and pad dimensions include side clearance and bottom overdig. Multiply by [1 + Excavation allowance ÷ 100].
- Continuous-footing rebar
- Continuous footing length × Rebar runs × [1 + Lap percentage ÷ 100]. Multiply by bar unit weight for estimated pounds.
Important: This is an estimating aid. Footing dimensions, reinforcing, excavation safety, soil capacity, and code requirements must be verified from approved project documents and qualified professionals.
How to Use This Calculator
- Mark every continuous footing run on the home plan.
- Add all matching runs and enter their combined length in feet.
- Enter the specified width and depth for that continuous footing group.
- Enter matching pad footing dimensions and the number of pads.
- Add realistic concrete waste and excavation planning allowances.
- Enter bag yield only when you need a bag estimate.
- Enter longitudinal rebar details from the structural notes.
- Calculate, review the result, then export the summary if needed.
- Repeat for footing groups with different sizes or reinforcement.
Planning Footings From a Home Plan
A home plan gives a useful footing map. It shows exterior walls, bearing lines, columns, and step locations. Measure each continuous run once. Include inside bearing walls when the design requires them. Keep garage, porch, and retaining work separate. Their footing sizes often differ. This calculator combines the measured runs into one practical takeoff.
Create a marked-up plan sheet for the estimator. Highlight measured runs, pad locations, footing transitions, and omitted areas. A second review catches repeated lines and incomplete connections.
Read Dimensions Before Ordering
Use the plan dimensions and structural notes together. The drawing scale can help with checks. It should not replace written dimensions. Enter the specified footing width and depth. Add pad footings for posts or concentrated loads. Record each pad size separately when sizes vary. Run the calculator again for every footing group. This prevents one large footing from hiding smaller details.
Separate Concrete From Excavation
Concrete volume follows the designed footing dimensions. Excavation needs extra width and depth for forming, access, and cleanup. The side-clearance and bottom-overdig fields estimate that extra earthwork. Soil swell then adjusts the excavation figure. These values support scheduling and disposal planning. They do not replace a trench safety plan. Confirm slopes, shoring, water control, and local requirements before digging.
Allow for Field Waste
Concrete waste covers small losses, uneven trench bottoms, and placement changes. A modest allowance is common for estimating. The correct amount depends on site conditions and delivery practice. Avoid using waste to cover uncertain dimensions. Recheck the plan instead. The calculator reports cubic feet, cubic yards, and estimated bag count. Use cubic yards for ready-mix orders. Use bag counts only for smaller pours.
Review the Takeoff With the Team
Compare the result with the drawing schedule before work starts. Check that every footing length has been included. Verify that units are correct. Inches and feet are easy to mix. Confirm rebar requirements with the structural drawings. The rebar estimate is limited to continuous-footing longitudinal bars. It does not include ties, chairs, dowels, hooks, laps beyond the selected allowance, or pad reinforcement. Use this page for quantity planning only. A licensed design professional must confirm footing sizes, reinforcement, soil capacity, and code compliance. Accurate plans produce safer, cleaner, more predictable concrete work.
Frequently Asked Questions
1. Does this calculator design a footing?
No. It estimates quantities from dimensions you enter. Footing design depends on loads, soils, reinforcement, frost depth, drainage, and governing requirements. Use approved drawings and qualified professionals to select actual footing sizes.
2. What is a continuous footing?
A continuous footing runs beneath a wall or line of support. It spreads load over a longer soil area. Enter the total length of all matching continuous runs for one footing size.
3. What is a pad footing?
A pad footing is an isolated concrete base under a post, column, or concentrated load. Enter its count, length, width, and thickness. Calculate separate groups when pad dimensions differ.
4. Why are footing width and depth entered in inches?
Home plans commonly list footing cross-sections in inches. The calculator converts inches to feet before multiplying volume. This reduces manual unit conversions during the takeoff.
5. What does concrete waste allowance cover?
It is an estimating allowance for small placement losses, irregular excavation, and field variation. It should not replace accurate plan measurements. Confirm the delivery quantity with the concrete supplier and project team.
6. Is excavation volume the same as concrete volume?
No. Excavation is usually larger because trenches need working room and may be dug deeper for cleanup. This calculator reports excavation separately using the clearance, overdig, and allowance values you provide.
7. Can I use the bag estimate for ready-mix ordering?
Use cubic yards for ready-mix ordering. The bag figure is mainly for small pours. Bag yields vary by product, so enter the manufacturer’s stated yield before relying on the result.
8. Does the rebar result include pad reinforcement?
No. The rebar estimate covers longitudinal bars in the continuous footing length only. It excludes pad mats, dowels, hooks, chairs, ties, and special reinforcement shown on structural drawings.
9. How should stepped footings be measured?
Split stepped footings into sections with matching width and depth. Run a calculation for each section. Add the ordered concrete quantities after applying the correct waste allowance to each group.
10. Can I measure from drawing scale alone?
Use written dimensions first. Drawing scale can help identify missing runs or verify a takeoff. It should not override dimensions, schedules, or structural notes on the approved document set.
11. What should I verify before ordering concrete?
Verify footing sizes, total lengths, pad count, steps, thickened areas, reinforcement, access, placement sequence, supplier minimums, and the selected waste allowance. Confirm final quantities with project documents and responsible professionals.
Accurate plans produce safer, cleaner, more predictable concrete work.