What Size Bore Pump Do I Need? Sizing Chart and the Pump to Buy
The bore pump size you need is the pump that fits your casing and delivers your flow at your total head, where total head is the pumping water level, plus the lift to the tank or house, plus pipe friction, plus any pressure you want at the outlet. For most Australian houses pumping to a tank, that works out to a 4 inch, 1HP, 240V pump like the Tuhorse A-12 at $963.
Horsepower is not the answer. Two 1HP pumps in our range lift 17 metres and 98 metres respectively. Same motor, different impellers, completely different jobs. People who ring up asking for "a 1HP bore pump" have asked the wrong question, and the four steps below fix that.
Skip ahead: jump to the sizing chart, or browse every submersible bore pump we sell.
Step 1: Measure the bore casing
Casing diameter sets the maximum pump diameter: a 4 inch pump needs a 4 inch or larger casing, a 6 inch pump needs 6 inch or larger, and a 3 inch casing limits you to a 3 inch pump.
Get the number from the drilling report, or measure the inside diameter at the bore head. Do not guess from the outside of the pipe. A 3 inch bore is common on older properties, and the Tuhorse 3 inch T-22 (70 metres, 50 L/min, $973) exists for exactly that reason. Everything else in this guide assumes 4 inch unless it says 6 inch.
Step 2: Work out total head
Total head for a bore pump is pumping water level plus vertical lift above the bore head plus pipe friction plus outlet pressure, with every bar of pressure counting as 10 metres.
| Part of total head | Where to get it | Typical house bore |
|---|---|---|
| Pumping water level | Drilling report or yield test (not the standing level) | 20 to 50m |
| Lift above bore head | Height of the tank inlet or house above the bore | 0 to 15m |
| Pipe friction | Pipe size, length and flow (rule of thumb below) | 3 to 10m |
| Outlet pressure | 0 into a tank, 10m per bar direct to a house | 0 or 30m |
The pumping water level is the one people get wrong. The standing level is where the water sits when nothing runs. Switch the pump on and the level drops, sometimes by 10 or 20 metres. Size on the drawn down number.
Pipe friction, as a rough rule of thumb only: allow around 3 to 5 metres for a 100 to 200 metre run of 32mm poly at house flows, and more if the pipe is smaller or the run is longer. If friction is eating more than about a quarter of your total head, the pipe is too small, and a bigger pipe is cheaper than a bigger pump.
Step 3: Decide the flow you need
The flow a bore pump needs comes from how the water is used: a house pumping to a tank needs 20 to 40 L/min, stock and irrigation are worked back from litres per day divided by pumping hours.
- House into a tank: 20 to 40 L/min is plenty, because the tank and a pressure pump handle the peaks.
- House direct, no tank: 30 to 50 L/min, since the bore pump is serving every tap at once.
- Stock: rule of thumb only, cattle drink around 50 to 100 litres a head a day in summer, sheep around 5 to 10. 150 cattle at 80 litres is 12,000 litres a day, or 25 L/min over 8 hours.
- Irrigation: add up the sprinklers or drippers running at once. This is where flow jumps into the hundreds of litres a minute.
Then check the bore yield. A pump that pulls more water than the bore gives will drain it, run dry and cook itself. If the drilling report says the bore yields 30 L/min, a 117 L/min pump is not an upgrade. It is a problem.
Step 4: Check your power supply
Single phase 240V bore pumps top out at about 3HP, so a job needing more than that needs a 415V three phase supply.
The 3HP 240V pumps draw around 14A running, which is a real load on a long rural supply. Get your electrician to confirm the supply and the cable size down the bore before you order. No power at the bore at all? A solar bore pump is the answer, and our best solar bore pumps guide covers how those are sized.
Bore pump sizing chart
This bore pump sizing chart matches total head and flow to a live Tuhorse 4 inch or 6 inch package, with the pump's maximum head comfortably above the working head.
| Your total head | Flow you need | Pump to look at | Max head / max flow | Supply | Price |
|---|---|---|---|---|---|
| Up to 30m | Up to 40 L/min | S-08 0.5HP | 69m / 35 L/min | 240V | $893 |
| Up to 30m | 80 to 110 L/min | BF-06 1HP | 46m / 117 L/min | 240V | $963 |
| 30 to 60m | 20 to 50 L/min | A-12 1HP | 98m / 58 L/min | 240V | $963 |
| 60 to 90m | 20 to 50 L/min | A-16 1.5HP | 129m / 58 L/min | 240V | $998 |
| 90 to 120m | 20 to 50 L/min | A-20 2HP | 162m / 58 L/min | 240V | $1,088 |
| 120 to 180m | 20 to 50 L/min | A-30 3HP | 236m / 58 L/min | 240V | $1,463 |
| 60 to 100m | 80 to 110 L/min | BF-18 3HP | 133m / 117 L/min | 240V | $1,363 |
| 100 to 180m | 80 to 110 L/min | BF-32 5.5HP | 232m / 117 L/min | 415V | $1,873 |
| Up to 60m | 400 to 600 L/min | ES-06 10HP (6 inch) | 88m / 633 L/min | 415V | $3,063 |
Prices current as of November 2026, AUD including GST. Maximum head and maximum flow are the two ends of the pump curve and do not happen at the same time. Treat this chart as a starting point, then confirm the flow at your exact head on the curve on each product page.
The pattern to notice: inside one series the flow stays the same and head climbs with horsepower. The A series always tops out at 58 L/min, the BF series at 117 L/min. So pick the series for your flow first, then climb the ladder until the head is covered.
Worked examples
These four worked examples show the full calculation from bore details to the pump we would actually sell for each job.
House pumping to a tank
A house bore pumping to a header tank needs about 41 metres of head here, so the Tuhorse A-12 1HP is the pump. Pumping water level 30 metres, tank 6 metres above the bore head, 150 metres of 32mm poly adding about 5 metres, no outlet pressure because it fills a tank. 41 metres at 30 L/min sits comfortably on a pump rated to 98 metres. The cheaper 0.75HP A-08 (66 metres) would technically do it, with less margin for a bore that drops in a dry summer. We would spend the extra $70.
House pumping direct with no tank
A bore pumping straight into a house at 3 bar needs about 80 metres of head here, which makes the 1.5HP A-16 the right pump. Pumping water level 40 metres, 5 metres of lift, 5 metres of friction, plus 30 metres for 3 bar. The A-12 tops out at 98 metres, and at 80 metres it is near the end of its curve with very little flow left. The A-16 at $998 delivers properly at that head.
Stock bore feeding troughs
A deep stock bore at 85 metres of total head and 25 L/min suits the A-16 at the bottom of its range or the 2HP A-20 with margin. Pumping water level 70 metres, 10 metres up to a ridge tank, 5 metres of friction on a long run. Cattle numbers grow and bores drop in drought, so we would pick the A-20 at $1,088 and stop thinking about it.
Shallow bore for garden irrigation
A shallow garden bore needing 100 L/min at about 20 metres of head suits the BF-06, not a deeper A series pump. Pumping water level 12 metres, ground level tank, 8 metres of friction and sprinkler pressure combined. The A-12 would lift it easily and deliver half the water. The BF-06 uses the same 1HP motor and moves up to 117 L/min. Same price, twice the water, because the impellers suit the job.
Going bigger than a garden, into hundreds of litres a minute for paddock irrigation, means a 6 inch bore and three phase power. The Tuhorse 6 inch ES-06 moves up to 633 L/min with a maximum head of 88 metres, for $3,063.
Can a bore pump be too big?
Yes, an oversized bore pump is a real fault, not a safety margin: it can pull the bore dry, cycle on and off, draw sand and burn out early.
Buy for the head you have plus a sensible margin, and never for more flow than the bore yields. If you are not sure of the yield, get the bore tested before buying anything bigger than a house pump. A pressure switch and dry run protection are cheap compared with a pulled pump and a contractor's day rate.
What else you need besides the pump
Every Tuhorse bore pump package includes the pump, motor and starter or control box, but not the poly pipe, stainless safety cable, drop cable or installation.
Use stainless cable to hold the pump, not rope. If the pump feeds a tank, you will usually want a surface pressure pump on the house side, and our multistage pressure pumps handle that. For a shallow well where you want the motor above ground, a deep well jet pump is the alternative. Electrical connection must be done by a licensed electrician, and bore work by a licensed driller where your state requires it.
Want the shortlist rather than the maths? Our best submersible bore pumps guide ranks the picks by job, and the Tuhorse bore pump review covers what these pumps do well and where they fall short.
Frequently asked questions
What size bore pump do I need for a house in Australia?
Most Australian houses pumping from a bore to a tank need a 4 inch, 1HP, 240V submersible bore pump such as the Tuhorse A-12, rated to 98 metres of head and 58 L/min, at $963 as of November 2026. A house pumping direct with no tank at 3 bar usually needs the 1.5HP A-16 because the pressure adds about 30 metres of head.
How deep can a 1HP bore pump pump from?
A 1HP bore pump can pump from anywhere between about 17 and 120 metres depending on its impellers, so horsepower alone does not tell you the depth. In the Tuhorse range the 1HP MA-03 tops out at 17 metres for high flow, the BF-06 at 46 metres, the A-12 at 98 metres and the S-14 at 120 metres for low flow.
How do I calculate total head for a bore pump?
Total head for a bore pump is the pumping water level, plus the height from the bore head to the tank or house, plus pipe friction, plus outlet pressure at 10 metres per bar. For example, 30 metres to the water, 6 metres up to a tank and 5 metres of friction gives 41 metres of total head.
What HP bore pump do I need?
The HP bore pump you need follows from total head and flow, not the other way round: most house and stock bores land between 1HP and 2HP on 240V. Pumps above about 3HP need a 415V three phase supply.
Can a bore pump be too powerful for my bore?
Yes, a bore pump that pulls more water than the bore yields will draw the water down to the pump, run dry, suck sand and fail early. Size the flow to the bore yield in the drilling report or a pump test, and fit dry run protection.
Send us your bore details
Send us your casing size, standing and pumping water level, tank or house height, pipe length, power supply and what the water is for, and we will tell you the pump to buy. It takes a few minutes and it is free.
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This guide is general information for Australian property owners and is not a substitute for advice on your specific bore and site. Pipe friction and stock water figures are rules of thumb. Electrical work must be done by a licensed electrician, and bore work by a licensed driller where your state requires it. Confirm final sizing with us before you buy.