Concrete Footing Cost Calculator

Concrete footings typically run $5 to $25 per linear foot installed, so a standard residential strip footing around a 150-foot foundation perimeter is often about $1,500 to $3,500. The drivers are the footing size (a standard 16×8 footing is cheapest; heavy or deep frost-depth footings cost more), the reinforcement (plain concrete vs. standard or engineered rebar), the soil conditions (soft/clay or rocky ground adds cost), and how the trench is excavated (open machine access vs. tight hand digging). Footings are a relatively small part of a total foundation cost but a critical structural one. Larger structural footings, difficult soil, rocky digging, and hand-dug access all push the per-foot cost toward the high end. Enter your footing length, size, reinforcement, soil, and excavation method in the calculator to anchor the estimate.

A concrete footing is the wide, reinforced concrete base that sits below a foundation wall, column, post, or other structure and spreads the building's load onto the soil. Because it's wider than the wall it supports, it distributes weight over a larger area so the structure doesn't sink, settle unevenly, or crack. Footings are poured at the bottom of an excavated trench (or hole, for isolated pier footings) and must bear on stable, undisturbed soil — and in cold climates, extend below the frost line so freezing ground doesn't heave them. Virtually every permanent structure relies on properly sized and placed footings for stability: houses, additions, garages, decks, retaining walls, columns, and load-bearing fences. The footing is, quite literally, what keeps a structure from moving — which is why it's code-regulated and often inspected before the pour. The calculator estimates the footings specifically.

They work together but aren't the same. The footing is the wide concrete base at the very bottom that contacts and spreads load onto the soil; the foundation (a foundation wall, stem wall, or slab) sits on top of the footing and supports the structure above. Think of the footing as the 'feet' and the foundation wall as the 'legs.' A footing is poured first in a trench, then the foundation wall is built or poured on top of it — often tied together with rebar dowels and a keyway so the two lock as a unit. This calculator estimates the footings specifically — the excavation, forming, reinforcement, and concrete for the strip footing — which is one component of a complete foundation. Full foundation walls, slabs, or basements are separate, larger scopes; the site has other calculators for those. When comparing quotes, confirm whether a 'foundation' bid includes the footings.

Footing depth is governed by two things: reaching stable, undisturbed soil and getting below the frost line. In cold climates, footings must extend below the local frost depth — anywhere from about a foot in mild regions to four feet or more in the far north — so freeze-thaw cycles don't push the footing up and crack the structure (frost heave). They must also bear on firm, load-bearing soil, not loose fill or topsoil. Local building codes (and the IRC footing tables) specify minimum depths and dimensions for your area, and an engineer may be required for unusual soils or heavy loads. This is exactly why a deep frost-depth footing costs more than a shallow one — far more excavation and concrete. The calculator's frost-depth option reflects that. Always build to your local code's required depth; an under-depth footing is both a structural risk and an inspection failure.

It depends on the application and local code. Many residential strip footings are reinforced with rebar — typically two or more horizontal bars running the footing's length — to add tensile strength, help the footing span minor soft spots in the soil, and resist cracking; code often requires it, especially for larger footings, poorer soils, or seismic areas. Some small, lightly-loaded footings on very good soil may be allowed as plain concrete. Heavier structural footings and those carrying concentrated loads use more or engineered reinforcement designed by an engineer. Rebar is cheap relative to the cost of a footing failure, so it's commonly included. The calculator lets you choose none, standard rebar, or engineered reinforcement to match your project. Follow your local code and any engineer's specifications — don't omit rebar to save a few dollars on a structural element.

Footing size (width and thickness) is set by the load it carries and the soil's bearing capacity. A common residential strip footing for a one- or two-story home is roughly 16–20 inches wide and 8 inches thick, but heavier structures, weaker soils, or concentrated loads call for wider and thicker footings to spread the load adequately. A general rule of thumb is that the footing should be about twice the width of the wall it supports, but the precise size should come from the building code's prescriptive tables or, for non-standard situations, an engineer's calculation based on your soil and loads. Undersized footings lead to settling and cracking; oversized ones waste money. Soft or clay soil generally needs a wider footing (which the calculator captures via the soil factor). The calculator offers standard (16×8), heavy (24×12), and frost-depth options to reflect different size requirements.

Usually yes — when a contractor quotes a full foundation, the footings are typically part of that scope, poured first as the base for the walls or slab. But if you're pricing footings on their own — for a deck, a retaining wall, a fence, a porch, a room addition tying into an existing structure, or a standalone structural element — they're quoted separately, which is what this calculator estimates. It's always worth clarifying with your contractor whether a foundation bid includes the footings, the excavation, the reinforcement, and any required drainage, since these are sometimes listed as separate line items. Knowing the per-linear-foot footing cost helps you understand and compare quotes for the structural base of any project, and spot whether a 'cheap' foundation bid has quietly excluded the footing work.

For a typical residential project, excavating, forming, reinforcing, and pouring the footings often takes just 1 to 3 days of on-site work, depending on length and complexity. The trench is dug to the required depth, forms are set where needed and reinforcement placed, an inspector usually checks the trench and rebar before the pour (a code 'footing inspection'), and then the concrete is placed and finished. After pouring, the concrete cures — it's typically firm enough to build the wall on within a few days, though it keeps gaining strength for about 28 days. Difficult soil, rocky excavation, deep frost footings, tight hand-dug access, and weather can extend the timeline. Because the footing is the first, load-bearing step and is often inspected before the next stage, getting it right is well worth the time — a rushed or unapproved footing can stall the whole project.

Frost heave is the upward movement of soil (and anything resting on it) when water in the ground freezes and expands. In cold climates, moisture in the soil can swell with enough force to lift a footing several inches, and because the heave is uneven, it cracks foundations, tilts decks and posts, and racks structures. The fix is depth: a frost-depth footing is dug below the local frost line — the maximum depth to which the ground freezes — so its bearing surface sits in soil that stays unfrozen year-round and doesn't swell. Frost depths vary widely (roughly a foot in mild areas to 4+ feet in the far north), and local code specifies the minimum for your area. This is why a frost-depth footing costs more than a shallow one — much more excavation and concrete. Skipping the depth in a cold climate is a classic, expensive mistake; the calculator's frost-depth option prices it correctly.

For most permanent structures, yes. Footings are structural and code-regulated, so a building permit is typically required, and the work usually includes a footing inspection — an inspector checks the trench depth, width, soil bearing, forms, and rebar placement before any concrete is poured (once it's poured, the work is hidden, so inspection has to happen first). Decks, additions, retaining walls over a certain height, and new structures generally need this. The inspection protects you: it confirms the footing reaches proper depth and stable soil and is reinforced to code before you build on it. Some jurisdictions also require engineered drawings for unusual soils or heavy loads. The calculator includes an engineering/inspection add-on to reflect this cost. Don't pour footings without the required permit and inspection — an unapproved structural footing can mean tear-out, fines, and problems at resale. Confirm requirements with your local building department.