Work it out.
Calculators tailored to plumbing: find the water velocity, work out the heat output, size the pump and expansion. Enter your own values — the result updates live.
What do you want to find out?
Directory
Choose the question that resembles yours — then we open the right calculator.
- § 01How fast does the water run in the pipe at a given flow rate — and is it above the guideline limit?Water velocity in pipe →
- § 02How many kW does a given flow carry at a specific ΔT between supply and return?Heat output from water flow →
- § 03How many litres of water are in the pipe — and how much per metre?Pipe content (volume) →
- § 04How much power does the pump deliver to the water — and what does it draw at the shaft?Pump power →
- § 05How long does it take to heat, say, a hot-water cylinder at a given power output?Heating-up time for tank →
- § 06How much volume must the expansion vessel be able to take up when the system heats up?Expansion volume →
- § 07How large a pressure drop does the pipe and its fittings give at a given flow — and is the speed too high?Pipe pressure loss →
- § 08How large a rainwater flow should roof downpipes and drains be dimensioned for?Roof drainage (rainwater) →
- § 09Does the hot water system's measured temperatures meet legionella requirements?Legionella temperature check →
- § 10How many watts does the radiator emit at a different mean temperature difference than the nominal?Radiator heat at ΔT →
- § 11How long does it take to heat a hot water tank from cold water to target temperature at a given power?Heating time for hot water tank →
- § 12How many metres of underfloor heating hose should I lay for a given area — and how many circuits?Floor heating hose — length and circuits →
- § V1Can I get the entire system specification — heating requirement, hot water, expansion and component selection — from my house at once?Complete plumbing system →
- § 13Does the sewer pipe have enough fall to the connection, or is a pump needed?Sewer fall →
- § 14How large should the expansion vessel be, and what pre-pressure and fill pressure should the system have?Expansion vessel size →
- § 15Which kv should valve have to give right flow at certain pressure drop?Valve and kv value →
- § 16How many millimetres does the pipe move when it gets hot, and how long should the bend leg be?Pipe thermal expansion →
Step A — Flow & flow rate
The hydraulics: the velocity of the water in the pipe and how much fluid is held in the run.
Step B — Heating & energy
The energy balance: how much power the flow moves, and how long it takes to heat up.
Step C — Systems & components
Size the pump and expansion vessel from your own system and pump data.
Pump power
What does the pump draw?
Expansion volume
How much does the water expand?
Floor heating hose — length and circuits
How many metres of hose do I need?
Expansion vessel size
How large a container, and what pre-pressure?
Pipe thermal expansion
How much does the pipe work, and how long should the leg be?
Step D — Drainage & rainwater
Drainage of rain and wastewater: the size of the flow the drain must be able to handle according to DS 432.
Step E — Hygiene & safety
Inspection against standard requirements — e.g. legionella temperatures in hot water for use according to DS 439/BR18.
Step V — Directory
Guided inspection of the entire system at once: the house's heating needs, hot water, expansion and component selection — pure geometry on your own answers.
Tools that work in all subjects
Maths and templates that work in every trade — and at school. Every tool shows the formula and the working with your own numbers.
- Pythagorasa² + b² = c²Find the missing side, set out a right angle, check whether a room is square, and find the space diagonal.
- Area and perimeterm²Rectangle, triangle, trapezium, circle and composite shapes — area and perimeter.
- Volume and surface aream³ · lBox, cylinder, cone, sphere, pyramid, prism, pipe and frustum — also in litres.
- Percent%Percentage of, how many per cent, percentage change, discount and VAT.
- Scale and ratios1 : 50From drawing to reality, area and volume to scale, the rule of three and dividing in a ratio.
- Unit convertermm ↔ mFrom mm to km, Pa to bar and kB to GB — with the unit staircase.
- Time calculations and the clockt : minTime between two clock times, add time, and 1.75 h = 1 h 45 min for the timesheet.
- Slope and fall% · ° · 1:xFall from level to level, in per cent, per mille, degrees and mm per metre — and the height difference.
- Material consumption including wastem² + %Boards, paint, battens at c/c spacing and packs — for a composite surface or a whole room, with waste.