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Construction Calculators for Site Work

Formula-based calculators for concrete, slope, drainage, excavation, structural checks, and material takeoffs — built on real construction math.

Concrete Volume & masonry Slope Grade & drainage Sitework Asphalt & excavation Loads Structural checks

Explore Construction Calculator Clusters

Concrete, Cement, Masonry & Rebar

27 calculators for concrete, block, rebar, and retaining walls — everything before you pour.
Aggregates, Stone, Sand & Base

17 calculators for gravel, sand, and stone base material — tonnage and yardage before delivery.
Driveway, Paving & Sitework

13 calculators for asphalt, gravel, and excavation work — driveways and sitework, start to finish.
Layout, Grade & Slope

8 calculators for percent grade, elevation, and squaring up a site with the 3-4-5 rule.
Plumbing, Drainage, Water & Tank

26 calculators for pipe slope, drainage fall, and tank volume — plumbing and water management.
Structural Loads & Forces

7 calculators for beam load, deflection, and bearing pressure — quick checks before you build.
Deck, Fence & Outdoor Structures

25 calculators for decking, fencing, and outbuildings — from post depth to baluster spacing.
Stairs, Angles & Curves

13 calculators for stairs, rafters, ramps, and miter cuts that need to land exactly right.
Mechanical, Fastener & Fabrication

23 calculators for bolt torque, thread sizing, and welds — fasteners and metal fabrication.
Measurement, Quantity & Conversion

8 calculators for board feet, cubic yards, and square footage — in US and SI units.
Flooring, Walls, Siding & Finishes

26 calculators for flooring, siding, drywall, and paint — finish-stage material takeoffs.
Roofing & Roof Framing

22 calculators for roof pitch, rafters, trusses, and shingles — framing to finish.

Frequently used construction calculators for concrete, slope, drainage, roofing, framing, and sitework estimates.

› Concrete Calculator Concrete calculator for slabs, footings, post holes, circular pours, and tube/ring shapes. Estimate cubic yards, cubic feet, cubic meters, waste, and concrete... Construction › Cubic Yard Calculator Cubic Yard Calculator estimates cu yd from length, width, depth, shape, quantity, and price, with cubic feet, material cost, material weights, and... Construction › Pea Gravel Calculator Pea gravel calculator estimates cubic yards, tons, cubic feet, bags, and material cost from area, depth, density, waste factor, and price per... Construction › Percent Slope Calculator Percent Slope Calculator calculates grade percentage from vertical rise and horizontal run using Percent Slope = (Rise ÷ Run) × 100, with... Construction › Pipe Slope Calculator Pipe Slope Calculator for finding slope from run and fall, with pitch, grade percent, angle, and minimum required drop by pipe diameter... Construction › Road Base Calculator Road Base Calculator to estimate tons, cubic yards, loose spread depth, truck loads, and material cost from area, compacted depth, density, compaction... Construction › French Drain Calculator French Drain Calculator estimates gravel volume, US tons or tonnes, fabric area, pipe displacement, excavation swell, and gravel cost from trench length,... Construction › Beam Deflection Calculator Simply Supported Beam Deflection Calculator to find mid-span deflection, max bending moment, support shear, beam stiffness, and deflection ratio for center point... Construction › Wood Fence Calculator Wood Fence Calculator estimates pickets or boards, posts, rails, concrete bags, fasteners, material subtotal, total cost, and cost per foot for vertical,... Construction

Latest Calculators

New tools are added across drainage, sitework, fabrication, layout, and roofing as the library expands.

› Voltage Rise Calculator A cable's length, size, and load current decide how much voltage builds up at a solar export point — this checks it... Electrical Calculators › Concrete Mix Calculator Concrete Mix Calculator estimates cement, sand, gravel, water and bags using volume × waste × 1.54 dry factor, split by mix ratio... Construction › Three-Phase Power Calculator Determine real, apparent, and reactive power for three-phase electrical loads using line voltage, current, and power factor for accurate system sizing Electrical Calculators › Battery Size Calculator Battery size calculator determines battery bank capacity, current draw, and discharge rate needed to reliably power a DC load efficiently over time. Electrical Calculators › Generator Fault Current Calculator Calculate a generator's subtransient, peak, and sustained fault currents, from power, voltage, and impedance to verify breaker and switchgear ratings. Electrical Calculators › Generator Current Calculator Determine full-load current, reactive power, engine sizing, breaker ratings and partial-load profiles for single-phase AC, three-phase AC or DC generator systems. Electrical Calculators › Transformer Fault Current Calculator Calculate three-phase, line-to-line, and line-to-ground short-circuit current at a transformer's secondary terminals from kVA, voltage, and impedance. Electrical Calculators › Transformer calculator Determine primary and secondary load current, turns ratio, and estimated fault levels for transformers from rated kVA and line voltage values entered. Electrical Calculators › Motor torque calculator Determine full-load and peak shaft torque for AC motors from power rating, operating speed, and service factor for coupling, gearbox, or shaft... Electrical Calculators
Why CalcFormula

What We Provide that Others Don’t

Every calculator is built around a real formula, not a black box — so you can check the math before you order material.

All Trades, One Library

250+ tools across concrete, drainage, structural, and fabrication — no jumping between five different sites.

Formula-Based Results

Every calculator page shows the actual formula and inputs behind the number, not just a black-box output.

Built for the Jobsite

Fully responsive, so you can run the numbers from your phone on-site, not just at a desk.

Checked Against Standards

Formulas are checked against ACI and manufacturer specs, and reviewed against field practice.

Free, No Sign-Up

Every calculator is free to use, with no account, paywall, or hidden cost.

Clear About Limits

Results are for planning and estimating. For structural, safety, or permit-sensitive work, we tell you to confirm with a professional.

Frequently Asked Questions

Common questions about using CalcFormula’s construction calculators.

Are CalcFormula’s calculators free to use?

Yes — every calculator on CalcFormula is free, with no account, sign-up, or hidden cost.

Do the calculators work in both US and metric units?

Yes. Calculators are built around US units (feet, inches, yards, tons) as well as SI/metric units (meters, liters, kilograms), so you can switch based on the job.

How accurate are the material estimates?

Each calculator uses a documented formula with stated inputs and assumptions, but real-world results vary with waste, compaction, moisture, product density, and site conditions. Treat results as a planning estimate, then confirm with your supplier before ordering.

Can I use these calculators for structural or permit-sensitive work?

These tools are built for preliminary planning and estimating. For structural, safety, permit, or code-sensitive decisions, confirm results with a qualified engineer or your local building department.

Where do the formulas come from?

Formulas are checked against ACI and manufacturer specifications and reviewed against field practice, not just textbook math.

Do I need an account to use a calculator?

No. There’s no login or account system — open a calculator, enter your numbers, and get a result.

Can I use CalcFormula on my phone at the jobsite?

Yes. Every calculator page is fully responsive, so you can run numbers on a phone or tablet on-site, not just at a desk.

Why do my supplier’s numbers differ slightly from the calculator?

Suppliers often round up to standard bag sizes, truckloads, or pallet quantities, and may add their own waste margin. Use the calculator as a planning baseline, then confirm final order quantities with your supplier.

Found an error or need a calculator that doesn’t exist yet?

Use the Report a Bug page to let us know what’s wrong or what’s missing, and we’ll review it.