What Can a 7×5 Trailer Carry?
The 7×5 is the most popular box trailer size in Australia, and the first question everyone asks is simple: will my stuff fit? The honest answer is that a 7×5 ft box trailer has two separate limits: how much space it has, and how much weight it can legally carry. For heavy loads it's usually the weight that stops you first.
Independent guide based on typical Australian trailer specifications, VSB 1 and Queensland TMR guidance. Always confirm the figures on your own trailer's compliance plate.
The two limits
1. Space: deck and height
A 7×5 ft box trailer has a deck roughly 2.1 m long × 1.5 m wide (7 ft × 5 ft). Standard side walls are around 300–500 mm high, and an optional cage adds a further 600 mm or 900 mm for bulky, lightweight loads.
7×5 trailer dimensions
| Length | Width | |
|---|---|---|
| Feet (nominal) | 7 ft | 5 ft |
| Millimetres | 2100 mm | 1500 mm |
| Centimetres | 210 cm | 150 cm |
| Metres | 2.1 m | 1.5 m |
A note on the numbers: "7×5" is a nominal size, not a precise conversion. A true 7 ft × 5 ft is 2134 mm × 1524 mm, but Australian box trailers are almost always built to a rounded metric 2100 × 1500 mm internal deck. Individual builders vary by a few centimetres, and some quote external rather than internal size, so measure the actual trailer before you plan a tight load.
Side walls in centimetres: 30 cm, 45 cm or 50 cm; a cage adds 60 cm or 90 cm on top.
How many cubic metres is a 7×5 trailer?
The deck is 2.1 × 1.5 m = 3.15 m² of floor, so capacity is simply floor area × wall height, loaded level:
| Setup | Height | Capacity (level) |
|---|---|---|
| 300 mm walls | 0.30 m | ≈ 0.95 m³ |
| 450 mm walls | 0.45 m | ≈ 1.4 m³ |
| 500 mm walls | 0.50 m | ≈ 1.6 m³ |
| 300 mm walls + 600 mm cage | 0.90 m | ≈ 2.8 m³ |
| 300 mm walls + 900 mm cage | 1.20 m | ≈ 3.8 m³ |
Heaping a load above the walls adds roughly another 10–20%, but anything heaped must still be restrained and covered so nothing can fall off.
Capacity is not permission to fill it. Those cubic metres only matter for light, bulky loads. With about 450 kg of payload, soil at 1.2–1.5 tonnes per cubic metre fills only around a third of a cubic metre: you would hit the legal weight limit with the trailer barely a third full. Mulch at roughly 0.25–0.4 t/m³ is the opposite: you can genuinely fill the box, and a cage earns its keep. See the weight section below.
2. Weight: payload
Payload is the maximum load you can add, and it equals ATM − Tare (see our guide on ATM, GTM & Tare). A typical single-axle 7×5 ft box trailer with a 750 kg ATM and ~300 kg Tare gives about 450 kg of payload. Heavy-duty and braked 7×5 trailers can have a higher ATM (and therefore more payload), so always check the plate.
What fits (by space)
On a 2.1 m × 1.5 m deck, a 7×5 ft box trailer will typically take:
- A queen mattress (about 2.0 m × 1.5 m) laid flat. It just fits the deck.
- A fridge and a washing machine standing up, with room for boxes around them.
- A one-bedroom furniture move: lounge, drawers, mattress and boxes.
- Green waste, garden clippings and mulch: add a cage for volume.
- A motorbike, or a ride-on mower (measure first, because some are too long).
Not sure it fits? The 3D Load Planner lets you drop boxes, mattresses and whitegoods into a virtual 7×5 and see how they pack.
Where weight is the real limit
Space can fool you. Dense materials hit the ~450 kg payload long before they fill the trailer:
- Soil, sand and gravel: roughly 1.2–1.5 tonnes per cubic metre. Even a third of a cubic metre can exceed a 750 kg ATM trailer's payload while barely covering the floor.
- Pavers, bricks and firewood: a single pallet can be 500 kg+.
- Wet green waste: heavier than it looks after rain.
For these loads, fill by weight, not by volume, and check the number before you leave the yard.
Quick FAQ
How much weight can a 7×5 trailer carry? Around 450 kg for a common 750 kg ATM single-axle trailer (ATM − Tare). Heavy-duty models carry more, so check your compliance plate.
Will a queen mattress fit in a 7×5? Yes. A queen (about 2.0 m × 1.5 m) lies flat on the 2.1 m × 1.5 m deck. A king (about 2.0 m × 1.8 m) is wider than the deck and will overhang.
Can a 7×5 carry a cubic metre of soil? No. A cubic metre of soil weighs well over a tonne, far beyond a typical 7×5's payload. Load dense materials by weight.
What are the dimensions of a 7×5 trailer? The deck is about 2.1 m × 1.5 m (7 ft × 5 ft), with side walls commonly 300–500 mm.
What are 7×5 trailer dimensions in cm? About 210 cm long × 150 cm wide, with side walls of 30 cm, 45 cm or 50 cm. A cage adds another 60 cm or 90 cm of height.
How many cubic metres in a 7×5 trailer? About 0.95 m³ loaded level with standard 300 mm walls (3.15 m² of deck × 0.3 m). With 450 mm walls it's ≈ 1.4 m³, with 500 mm walls ≈ 1.6 m³, and with a 600 mm cage on 300 mm walls ≈ 2.8 m³.
How many cubic metres of mulch fits in a 7×5? With mulch the box fills before the weight limit does. At roughly 0.25–0.4 tonnes per cubic metre, a 450 kg payload is worth about 1.1–1.8 m³: more than the 0.95 m³ a 300 mm-walled 7×5 holds. That is exactly why a cage pays off for mulch and green waste, and why it does nothing for soil.
See what fits before you load. Use the 3D Load Planner to pack your items into a virtual 7×5, and the Compliance Auditor to check you're within the trailer's weight limits, with no sign‑up.
Independent reference only. Sizes and weights are typical values; confirm against your trailer's compliance plate and verify with TMR or a certified RPEQ engineer before purchasing, building or registering a trailer.