Earth auger for fence posts
Updated: October 2026
You have panels, a pile of posts, and an auger that may be the wrong width. An earth auger for fence posts has to cut the hole, not a socket the same size as the timber. UK trade guides, used here as a rule of thumb and not as Building Regulations, commonly want about 600 mm of depth for a typical 1.8 m fence and a hole about three times the post width. A 10 cm hand flight does not do that for a 100 mm post, and neither does the 150 mm bit on the Einhell. The prices sit in the [earth auger comparison](/hub/digging-tools/earth-auger). Peter F. compared the listings and public UK sources in October 2026. There was no lab test. A qualifying purchase can earn a commission at no extra cost to you.
You have panels, a pile of posts, and an auger that may be the wrong width. An earth auger for fence posts has to cut the hole, not a socket the same size as the timber.
You have panels, a pile of posts, and an auger that may be the wrong width. An earth auger for fence posts has to cut the hole, not a socket the same size as the timber. UK trade guides, used here as a rule of thumb and not as Building Regulations, commonly want about 600 mm of depth for a typical 1.8 m fence and a hole about three times the post width. A 10 cm hand flight does not do that for a 100 mm post, and neither does the 150 mm bit on the Einhell. The prices sit in the earth auger comparison. Peter F. compared the listings and public UK sources in October 2026. There was no lab test. A qualifying purchase can earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Diameter | Stated depth | Power | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Einhell Einhell GP-EA 18/150 cordless auger | 150 mm | 80 cm | Cordless 18 V | 9.0 | about £148.45 | View offer |
| Best value |  LONGRUN LONGRUN manual fence post auger | 100 mm | 54 cm | Manual | 8.4 | about £29.98 | View offer |
 Horti Power Horti Power 82 cc petrol earth auger | 100–300 mm | Extensions 40 and 60 cm | Petrol 82 cc | 0.0 | about £299 | View offer |
On this page
Depth and width, as a rule of thumb
BSW’s fencing guide, for a fence about 1,800 mm high, specifies a 2,400 mm post and a hole about 600 mm deep and about three times as wide as the post, and it tells you to check for services first. Jacksons Fencing gives a standard recommended depth of 600 mm and the same width idea, with gravel under timber so water can leave. DIY Doctor’s chart, for a 100 mm post with 1.8 m above ground, shows a hole about 300 mm wide and 600 mm deep.
Treat that as a trade rule of thumb, not as a statute. Clay, a gate, a corner, or an exposed site is where those guides expect more depth. A low sheltered panel is where you might stop short. The figure that changes the auger is the width: about 300 mm for a 100 mm post. How to run the machine without a snatch is on how to use an earth auger.
What the bits in this set actually cut
Put the bits in this comparison next to that 300 mm figure. The LONGRUN is a 10 cm flight with a stated dig depth of 54 cm, at £29.98. The VIDETOL is listed as 10 x 60 cm, at £17.99. Both are narrower than a 100 mm post plus any concrete. Reviewers have used them for bulbs and for the odd post hole. That shows the flight will move soil. It does not show a concrete collar around timber.
The Einhell GP-EA 18/150 includes a 150 mm bit and states 80 cm of drilling depth, at £148.45, with 4.5 from 752 reviews. UK reviewers set fence posts and hedging with it. That shows a 150 mm hole in clay, and a stop on stone. It does not show a 300 mm trade hole.
One manual listing, at £24.99, says 8 inch (200 mm) in the title and 15 cm in a bullet. Both figures are on the page. Do not pick 200 mm to make the fence sum work. The only kit in this set that lists a 300 mm bit is the Horti Power 82 cc petrol auger at £299, with 100 mm and 200 mm bits as well, extensions of 40 cm and 60 cm, and a stated weight of 25 kg. The amazon.co.uk listing has no star rating.
A 150 mm hole can still be the right job
A 150 mm bit is the right purchase when the post is a narrow metal spike, when you are drilling a pilot and opening the hole out with a spade, or when the fence is a short run of thin stakes rather than 100 mm timber in concrete. Einhell reviewers who set hedging were doing a real UK job. They were not disproving the geometry.
If you will not widen the hole by hand, change the bit or hire. The Worx 20 cm flight still misses 300 mm. The conflicting 200 mm and 15 cm manual listing is not a measurement you can take to the timber yard. Corners and gate posts are where a thin collar fails first. Clay does not add the missing diameter.
Concrete, gravel, and when to hire
Jacksons and BSW both point at gravel in the base of a timber post so water is not trapped against the end grain. The auger does not place that gravel. You bore, you lift the spoil, you add the stone, then you set the post and concrete if that is the build. Do not bore the fence line on a suspected cable. The Health and Safety Executive’s CIS65 sheet says not to use power tools within 0.5 m of a suspected route.
Hire is the practical way to get a wider flight for one Saturday. Hire Services (Southern) lists £35 for a one-person borer and £45 for a two-person borer for a day, excluding VAT. Tippers lists £40 a day excluding VAT, and Arrow Plant lists £37.40 for the first day of a one-person petrol borer, excluding VAT. Those are named counters, not an average, and deposits and delivery are extra. Against the unreviewed 25 kg Horti Power kit, a day’s hire is the smaller commitment for a single fence. Which power source to own is on petrol vs cordless earth auger.
Common questions
How deep is a hole for a 1.8 m fence?
A common UK trade rule of thumb is about 600 mm, which is also what DIY Doctor’s chart shows for 1.8 m above ground when depth is one third of that height. BSW’s guide for a fence about 1,800 mm high uses a 2,400 mm post and a hole about 600 mm deep. Gate posts, corners, clay, and exposed sites are where those guides expect more. It is supplier guidance, not a statute.
How wide should the hole be for a 100 mm post?
About three times the post width, which those same guides put near 300 mm. DIY Doctor’s table shows about 300 mm wide by 600 mm deep for a 100 mm post with 1.8 m above ground. The gap is for concrete around the timber, not for a hole that grips the post like a socket. A 10 cm auger is already narrower than the post itself.
Is the Einhell 150 mm bit enough for that post?
It is enough to bore a 150 mm hole, which UK reviewers have used for fence posts and hedging. It is not enough to match a 300 mm rule-of-thumb hole unless you open the sides out with a spade. The listing includes that 150 mm flight and states 80 cm of depth, at £148.45, without a battery. Depth on the listing and width in the trade guide are different limits.
Which auger in this set lists a 300 mm bit?
The Horti Power 82 cc kit at £299, together with 100 mm and 200 mm bits and extensions of 40 cm and 60 cm. The stated weight is 25 kg. The amazon.co.uk listing has no star rating and does not state a jam brake, a vibration figure, or the fuel mix. Listing a 300 mm bit is not the same as a reviewed record in clay.
Should I hire a wider bit for one fence?
Hire when you need about 300 mm once. Day rates before VAT at the shops named above sit around £35 to £45, against £299 for the only kit in this set that lists a 300 mm bit, or against a 150 mm cordless tool you would still widen by hand. If you already own a suitable battery and you accept the spade work, the 150 mm auger can still be the tool you keep.
Related pages
Sources
Public UK sources and the amazon.co.uk listing lines saved on 19 October 2026. No laboratory test.
- HSE — PUWER overview (retrieved 19 October 2026)
- Control of Vibration at Work Regulations 2005 (retrieved 19 October 2026)
- HSE — excavations (retrieved 19 October 2026)
- HSE — CIS65, avoiding danger from underground services (retrieved 19 October 2026)
- Energy Networks Association — Think before you dig (retrieved 19 October 2026)
- Einhell UK — GP-EA 18/150 Li BL-Solo (retrieved 19 October 2026)
- Worx UK — WG865E.9 40 V earth auger (retrieved 19 October 2026)
- Supply of Machinery (Safety) Regulations 2008, Schedule 2 (retrieved 19 October 2026)