Field utilities

Free tools

Field-ready calculators and converters for earthwork, utilities, materials, and light civil engineering. Use on-site or in the office — always verify critical quantities with project controls and engineering.

Unit converter
Convert length, area, volume, and mass between US customary and metric units.
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Percentage calculator
Solve part/whole percentages, percent change, and ratio-style comparisons.
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Volume calculator
Rectangular pits, trenches, and cylinders — cubic yards and cubic feet.
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Material weight (CY → tons)
Estimate tonnage from volume using typical aggregate and soil densities.
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Round pile concrete
Concrete volume for round piles from diameter and length; optional quantity.
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Bank / loose / compacted
Translate volumes using swell and compaction yield factors common in earthwork.
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Grade & slope
Convert rise/run to percent grade and ratio for layout and checks in the field.
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Pipe internal volume
Estimate internal volume of a pipe run from ID and length for utility work.
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RCP concrete & bore
Reinforced concrete pipe: bore volume plus concrete shell from ID, wall thickness, and run length.
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Pipe run (bore & wall)
Bore volume and wall annulus from ID, optional OD or wall thickness, and length — with a dual-ring diagram.
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Pipe & box bedding
Round pipe (water/sanitary PVC, RCP, HDPE) and box culvert bedding — pick a size, auto-fill OD and side clearance, get CY/LF and tons.
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Slope distance (2D)
From horizontal run and vertical rise: slope length, percent grade, and slope angle.
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Concrete slab volume
Rectangular slab: length, width, and thickness to cubic feet and cubic yards for flatwork estimates.
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Pressure & head (water)
Convert feet of water column to PSI (and kPa) for head checks and rough pump conversations.
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Flow rate converter
Convert between cfs, gpm, MGD, L/s, and m³/s for dewatering and line sizing discussions.
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Station / chainage
Add or subtract distance from a US-style station (e.g. 10+00) for quick chainage math.
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Drain or fill time
Time to move a volume at a steady flow rate — tanks, pits, and pump curves (steady-state only).
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These free calculators are for informal support and education only. S Thomas Construction is not responsible for errors, omissions, misuse, or any decisions, damages, losses, or unsafe practices based on them. By using any calculator on this site, you agree to the Terms of Use below.

This notice does not replace our general Terms of Service.