The problem with guessing

You pull into the site. It looks pretty level. You chuck a block under one wheel, drive on, check the bubble — still off. Add another block. Drive off, reposition, drive back on. Your partner is standing in the rain doing the signal. Twenty minutes later, you're close enough and you've decided that'll do.

Every Australian motorhomer has done this. It's not a skill issue — it's an information issue. You don't know how far off level your site actually is before you start. So you're guessing.

The fix is simple: measure first, place blocks second.

The formula

Ramp blocks raise your wheel by a fixed increment per step — typically somewhere between 35mm and 50mm depending on brand. To know how many you need:

📐 The calculation

1
Measure how many millimetres the low wheel needs raising. This is your "rise required."
2
Look up the step height of your specific ramp blocks (see table below).
3
Divide rise by step height. Round up to the next whole number. Blocks needed = ⌈ Rise (mm) ÷ Step height (mm) ⌉
4
Check your ramp's maximum stack. If you need more steps than your ramp allows, you'll need to reposition on a better part of the site.
Example: rise required = 78mm, using Camec blocks (38mm/step) → 78 ÷ 38 = 2.05 → 3 blocks

Step heights for common Australian ramp brands

These are the brands you'll find at most Aussie caravan suppliers. Step heights are approximate — always verify against your specific product, as manufacturers occasionally update designs.

Brand Step heights Max rise Notes
Camec (standard) ~38mm per step ~115mm (3 steps) Most common in Aus; fits between tandem axles
Tufway ~35mm per step ~105mm (3 steps) Budget-friendly; single and dual axle variants
Milenco Quattro 40mm, 80mm, 120mm, 160mm 160mm (4 steps) OzLevel Pro supports 4-step ramps like this
Redfoot Multi-Stage 40mm, 70mm, 100mm 100mm (3 steps) Larger footprint; better on soft ground
TRED GT ~38mm per step ~115mm (3 steps) Interlocking system; short enough for tandem axles
Mean Mother ~33mm per step ~100mm (3 steps) 0–100mm range stated; check your specific model
Fiamma Level Up ~30mm per step ~90mm (3 steps) Lighter; more common on campervans
Generic/unknown Measure with ruler Varies Enter your measured height into OzLevel settings
💡 Pro tip: Measure your ramp's actual step height once and record it. Manufacturers' stated heights are sometimes rounded. A quick measurement with a tape against a flat surface takes 30 seconds and makes every future calculation more accurate.

How to measure how far off level you are

This is the part most people skip — and it's why they end up doing multiple passes.

You have a few options:

Option 1 — Your phone (recommended)

Your phone contains a precision accelerometer — the same chip used in every spirit level app. Park the vehicle, open OzLevel (or any spirit level app), and it reads the exact angle of lean. OzLevel converts this angle to millimetres of rise required at each wheel based on your vehicle's track width.

OzLevel Pro then takes that rise figure and divides it by your specific block step height — giving you the exact block count before you've even opened the storage bay.

Option 2 — Bubble level inside the vehicle

Many motorhomes have a bubble level stuck to a wall or window. The problem: these only tell you which direction you're leaning — not by how much. You still end up guessing how many blocks to use.

Option 3 — Dedicated Bluetooth sensor

Products like SavvyLevel and the Oricom RVLS01 mount to your vehicle and pair with an app. Accurate, but $100–$350+ before you've started — plus something else to charge and pair. For most people, your phone does the same job.

How accurate does it need to be? Most RV fridges and appliances are rated to operate within ±3° of level — that's about 105mm of rise across a standard motorhome track width. A phone accelerometer on a static vehicle is accurate to well within that. You're levelling a motorhome, not calibrating a surveying instrument.

Front-to-back (pitch) vs. side-to-side (roll)

Most sites are primarily off in one direction — usually left-right (roll), because roads and campsites are often crowned or have lateral drainage fall. But sometimes you'll have both.

With roll only: raise the low side, done. With both roll and pitch: you need to level both axes simultaneously or in the right order. OzLevel's dual-axis mode shows both at once and tells you which wheels need raising — so you don't accidentally fix your roll and make your pitch worse.

The maths gets tedious when you're dealing with both axes. Which is another reason to let the app do it.

What if the site is too uneven for your ramps?

Sometimes the site simply can't be levelled with the ramps you have. Common causes:

OzLevel Pro includes a reposition vehicle warning — if the required rise exceeds your ramp's maximum, it tells you before you start wrestling with blocks. Move forward or back a metre, re-measure, and try again.

A note on slideout-equipped motorhomes

If your motorhome has a slideout, "perfectly level" isn't always ideal. A slideout seal pressed flat against the body with water sitting on top of it degrades faster than one with a slight downward bias draining water away.

OzLevel Pro's slideout seal protection mode biases the slideout side a few millimetres lower than perfect level — within appliance tolerances, but enough to encourage drainage. It's a small thing that protects an expensive seal over years of use.

The quick reference

Rise needed Camec (~38mm) Milenco Quattro Tufway (~35mm)
Under 38mm1 block1 step (40mm)1 block
39–76mm2 blocks2 steps (80mm)2 blocks
77–114mm3 blocks3 steps (120mm)3 blocks
115–160mm⚠️ Over max4 steps (160mm)⚠️ Over max
Over 160mmReposition — beyond ramp range
Skip the table entirely. OzLevel Pro reads your phone's sensors, knows your ramp brand and step height, and tells you exactly how many blocks each wheel needs — before you open the storage bay. Free to try. Pro is $9.99 AUD once, no subscription.

Summary

To calculate how many ramp blocks you need: measure the rise required in millimetres, divide by your ramp's step height, round up. The table above gives you quick reference figures for the most common Aussie brands.

But the real answer is: measure with your phone before you touch a single block. You'll place them right the first time, every time.