Plumbing Trade Math: Pipe Offsets, Slope, Flow & Fixture Units
Tape fractions and millimetres, 45° and rolling offsets, drain fall and grade, pipe volume and water weight, Q = V × A, fixture unit sizing, water heater first-hour rating and a job quote with a chart: 8 graded labs for apprentices and DIY planners.
The first lesson is free — no account needed.
About this course
A plumbing trade math course for apprentices, plumbers preparing for a trade exam and DIY planners, worked through one fictional plumbing firm's jobs in a spreadsheet. You turn tape readings in feet, inches and fractions into decimal inches and millimetres, find the travel of 45° and other offsets and solve rolling offsets with Pythagoras, calculate the fall, percent grade and end depth of drain runs, work out how many gallons and litres a pipe holds and what the water weighs, size supply pipes with Q = V × A and a velocity limit, total drainage fixture units and look up a pipe size in an illustrative table, size a tank water heater from the peak hour and its first-hour rating, and build a material estimate and quote with a chart. Tables and limits are illustrative, so always follow your local plumbing code. The first lab is free.
Lessons
- Tape Measure Math: Feet, Inches, Fractions & MillimetresFree
- Offsets: 45° Travel, Other Fitting Angles & Rolling Offsets Pro
- Drain Slope: Fall over Length, Percent Grade & Depth Pro
- Pipe Volume & Water Weight: Gallons, Litres & Pounds Pro
- Flow Rate & Velocity: Q = V × A for Supply Pipes Pro
- Fixture Unit Totals & Pipe Size Lookup Pro
- Water Heater Sizing: Peak Hour, Recovery & First-Hour Rating Pro
- Job Material Estimate & Quote with a Chart Pro