Mechanical, HVAC & Plumbing Calculators
HVAC sizing, pipe flow, pump head, tank volumes and shop math for the trades.
HVAC
- BTU Calculator for Room Air ConditionersCalculate how many BTUs of air conditioning a room needs from its size, sun exposure, occupants and kitchen use, using…
- AC Tonnage CalculatorConvert a cooling load in BTU per hour to air conditioner tons and the next standard size, convert tons to kW, and get…
- CFM CalculatorCalculate airflow in CFM from room size and air changes per hour, from a heat load and temperature difference, or from…
- Duct Size CalculatorSize round and rectangular HVAC ducts from CFM and friction rate with the equal friction method, and check velocity and…
- Heat Loss CalculatorCalculate a building’s heat loss in BTU per hour from walls, windows, doors, ceiling, floor and air leakage, with a…
- Heat Pump vs. Furnace Cost CalculatorCompare the yearly heating cost of a heat pump against a natural gas, propane, oil or electric furnace, using fuel…
- SEER Savings CalculatorCalculate yearly energy and cost savings from upgrading to a higher SEER or SEER2 air conditioner or heat pump, with…
- Dew Point CalculatorCalculate dew point from temperature and relative humidity, or relative humidity from dew point, with wet bulb…
Plumbing & Fluid
- Pipe Flow Rate CalculatorCalculate flow rate in gallons per minute from pipe size and velocity, find water velocity from flow, or size a pipe…
- Friction Loss CalculatorCalculate water pipe friction loss in feet of head and PSI with the Hazen-Williams equation. Schedule 40 and copper…
- Pump Head CalculatorCalculate total dynamic head (TDH) for a water pump from lift, pipe friction and outlet pressure, plus water horsepower…
- Water Pressure CalculatorConvert water height to PSI and PSI to feet of head, and find the static water pressure at an upstairs fixture.…
- Tank Volume CalculatorCalculate tank volume in gallons and liters for vertical and horizontal cylinders, rectangular tanks and capsule tanks,…
- Pool Volume CalculatorCalculate pool volume in gallons and liters for rectangle, round, oval and kidney pools with sloped bottoms, plus fill…
- Water Heater Sizing CalculatorSize a tank water heater by peak hour demand and first hour rating, or a tankless water heater by flow rate,…
- Drain Slope CalculatorCalculate drain pipe fall per foot and total drop over a run, or find the slope from a measured drop. Checks the IPC…
Mechanical
- Gear Ratio CalculatorCalculate gear ratio from tooth counts for simple and compound gear trains, with output speed, output torque and…
- Pulley and Belt Length CalculatorCalculate belt length from pulley diameters and center distance, or the center distance for a belt, plus driven pulley…
- RPM CalculatorCalculate RPM from surface speed and diameter, from wheel speed in mph, or from horsepower and torque, and convert RPM…
- Torque CalculatorCalculate torque from force and lever arm length, or from horsepower and RPM. Converts between lb-ft, lb-in, N·m and…
- Bolt Torque CalculatorCalculate bolt tightening torque and clamp load for SAE Grade 2, 5 and 8 and metric 8.8, 10.9 and 12.9 bolts, UNC, UNF…
- Horsepower CalculatorCalculate horsepower from torque and RPM, from volts and amps for DC, single-phase and three-phase motors, or from…
- Hydraulic Cylinder Force CalculatorCalculate hydraulic cylinder push and pull force from bore, rod and pressure, plus extend and retract speed, cycle time…
- Spring Rate CalculatorCalculate compression spring rate from wire diameter, coil diameter, active coils and material, or from a force and…
- Beam Deflection CalculatorCalculate maximum beam deflection, bending moment and stress for simply supported, cantilever and fixed beams with…
- Moment of Inertia CalculatorCalculate area moment of inertia, section modulus, radius of gyration and area for rectangles, tubes, round bars, pipe…
- Stress and Strain CalculatorCalculate axial stress, strain and elongation from force, area, length and modulus of elasticity, or find Young’s…
Shop & Fabrication
- Speeds and Feeds CalculatorCalculate spindle RPM and feed rate for drilling, milling and turning from cutting speed (SFM), tool or part diameter,…
- Drill Tap Size CalculatorFind the tap drill size for UNC, UNF and metric taps at any thread percentage, with number, letter, fractional and…
- Thread Pitch CalculatorConvert threads per inch to metric pitch and back, and find basic pitch diameter, minor diameter, thread height and…
- Sheet Metal Bend Allowance CalculatorCalculate sheet metal bend allowance, bend deduction, outside setback and flat blank length from thickness, inside…
- Weld Metal Weight CalculatorCalculate weld metal weight per foot and total filler metal needed for fillet, square groove, single-V and double-V…
- Steel and Aluminum Weight CalculatorCalculate the weight of steel, stainless, aluminum, brass and copper plate, bar, tube, pipe and angle by size and…
- Metal Cutting Cost CalculatorEstimate the cost per part for laser, plasma, waterjet or saw cutting from cut length, cut speed, pierces, machine…