Concrete & Foundations Calculators
11 free concrete & foundations calculators — standards-based, with formulas, worked examples, and no sign-up.
Concrete work has three distinct phases and this category has tools for each: proportioning the material, engineering the reinforcement, and quantifying the pour. Mix design follows ACI 211 — water/cement ratio against target strength, aggregate proportioning, SCM replacement — while the reinforcement tools implement chapter-and-verse code checks: development length and lap splices per ACI 318-19 §25.4 with its modification factors, anchor bolts per ACI 318-19 Chapter 17 with the full tension/shear failure-mode ladder, and crack width per Eurocode 2 §7.3 against the usual 0.3 mm serviceability limit.
Foundations get two entry points. The foundation design calculator is the complete workflow — Terzaghi, Meyerhof, or Hansen bearing capacity, settlement, then punching shear and flexural steel for the footing itself — and the pile foundation tool covers deep foundations with alpha, beta, and SPT-correlation methods per EC7 and ASCE practice. If you only need the geotechnical half (allowable pressure, no structural design), the standalone bearing capacity calculator in the geotechnical category is faster.
The estimating tools are deliberately separate from the design tools. Concrete volume converts formwork geometry to cubic yards and 60/80 lb bag counts with a waste allowance; rebar weight turns a bar schedule into tonnage with lap allowances; rebar scheduling produces BS 8666 shape codes and cutting lengths; brick & mortar and concrete steps handle masonry quantities and stair geometry with an IRC riser check. Design tells you what to build — these tell you what to order.
All Concrete & Foundations Tools
Foundation Design
Shallow foundation design with bearing capacity, settlement analysis, punching shear, and flexural reinforcement per ACI 318, Eurocode 7, and AS 2159.
Concrete Mix Design
Mix proportioning per ACI 211 with w/c ratio, aggregate sizing, and SCM replacement calculations.
Pile Foundation Design
Axial capacity and settlement analysis using alpha, beta, and SPT methods for driven and bored piles.
Rebar Scheduling & Detailing
Bar bending schedules and cutting length calculation with shape code library for reinforcement detailing.
Concrete Crack Width Calculator
Flexural crack width wk of reinforced concrete with crack spacing and limit check per Eurocode 2.
Development Length Calculator
Rebar development length, Class A/B tension lap splices, and compression development per ACI 318-19.
Anchor Bolt Design Calculator
Single cast-in anchor tension and shear strengths with governing failure mode per ACI 318-19 Ch.17.
Rebar Weight Calculator
Reinforcement steel mass from a bar schedule with totals by size in kilograms and tonnes.
Concrete Volume Calculator
Concrete quantity for slabs, footings, columns, and beams with bag count and cement/sand/aggregate breakdown.
Brick, Block & Mortar Calculator
How many bricks or concrete blocks a wall needs from its dimensions and openings, using published rates for US modular, queen, king and UK standard brick and 8/6/4 in CMU or custom unit sizes. Includes premixed mortar bags, masonry sand quantity, and pallet counts with a waste allowance.
Concrete Steps Calculator (Volume & Riser Layout)
Solid poured-concrete steps takeoff from the total rise: equal-riser layout rounded up against the IRC R311.7.5 7.75-inch maximum riser with a 10-inch minimum tread check, stepped-mass volume of width x riser x tread x n(n+1)/2 plus an optional full-height top landing, a 10% waste allowance with cubic-foot and cubic-yard totals, 60-lb (0.45 ft³) and 80-lb (0.60 ft³) premixed bag counts, and formwork quantities as riser board lineal feet plus the two stepped side profiles in square feet.
Frequently Asked Questions
Which bearing capacity method should I pick in the foundation tool?
Terzaghi is the classical baseline and fine for quick strip-footing checks in uniform soil. Meyerhof adds shape and depth factors and is the common default for rectangular footings. Hansen extends further with inclination factors for footings under moment or horizontal load. If the three disagree substantially, that spread is telling you the soil parameters, not the method, dominate the uncertainty — get better soil data.
Why does my development length come out so much longer than the old 12-inch rule of thumb?
ACI 318-19 §25.4 makes development length explicit in bar size, concrete strength, coating, and casting position — a top-cast epoxy-coated #8 bar in 3,000 psi concrete legitimately needs several feet. The calculator shows each modification factor so you can see what is driving the number, and computes Class B lap splices from the same basis.