Choose a mower wide enough to cover your open lawn comfortably, but small enough to get through the gates and turn around the beds without a struggle. Long, straight runs favour a wider cut. Short sections, narrow strips and awkward access often favour a more compact machine, even when the total grass area is quite large.
Start by measuring the lawn and its narrowest access point. Then compare the mower’s cutting width with its overall dimensions: a mower with a 50cm cut needs more than a 50cm gap. The wheels, deck and other projecting parts still have to pass through.
If you already have those measurements, the lawn mower buying guide compares suitable machines for different gardens and finishes.
Measure the grass you actually need to cut
Measure the lawn rather than the whole garden. A 12m by 10m rectangle is 120m², but a patio, large bed or pond within that outline reduces the area you mow. Add separate front and rear lawns together when thinking about the work and battery capacity.
For an irregular lawn, divide the shape into manageable rectangles and triangles, measure those and add their areas. A rough sketch is useful: mark the trees, island beds, narrow links and changes of level as well as the dimensions.
Keep the separate areas on your notes. Two lawns totalling 300m² can be very different jobs. One open rectangle may offer long, uninterrupted runs; a front lawn and several grass strips around planting can involve much more turning and moving between sections.
Also note where the mower lives and where you empty the collector. A longer walk to the compost heap or green-waste collection point adds work that a wider blade will not remove.
Check the complete mower against gates and passageways
Cutting width describes the strip of grass the mower cuts. For access, you need the width of the complete machine. Look for the manufacturer’s product dimensions and check whether they describe the mower assembled for use, folded for storage or packed in its box.
Measure the clear opening with the gate in the position you can actually hold it. Allow for hinges, latches, a wall that narrows the approach and anything projecting into the passage. A gap measured between fence posts can be wider than the route available to the wheels.
Then look beyond the gate. If the mower has to turn immediately into a side passage, its length matters too. Include the handle and any collector that will remain attached. A straight doorway and a tight right-angle entrance need different amounts of room.
If the fit looks close, mark the mower’s published footprint on the ground with removable tape or pieces of card. This helps you picture the space, although handling the assembled mower is more useful for checking a difficult turn. Leave comfortable clearance for guiding it through rather than planning to scrape past on every cut.
Do the same check for a narrow lawn between raised beds. The mower must fit between the hard edges while keeping its wheels supported. You may still need shears or a trimmer for grass the blade cannot reach beside a wall.
Match cutting width to the lawn’s shape
On a broad, fairly open lawn, a wider cut reduces the number of parallel runs needed to cover the grass. The RHS mower guide recommends considering a wider cut for larger lawns.
On a lawn broken up by trees, curving beds and stepping stones, more of the job is spent lining up short passes. A compact mower can be easier to place accurately, particularly when the handle needs to swing around a corner.
| What your lawn is like | What to prioritise |
|---|---|
| Long, open runs with generous turns | A wider cut, with drive if sustained pushing is tiring |
| Short runs around beds and trees | Manageable overall dimensions and easy steering |
| Narrow grass strips or restricted access | A mower that fits the tightest section comfortably |
| Separate lawns linked by steps or paths | Weight and safe movement between areas as well as cutting width |
Pay attention to the turning space at each end of a run. A mower may travel neatly along a narrow strip yet need awkward reversing every time it reaches the end. Compare the room available with both the machine and the person operating it.
Allow for overlap when comparing wider cuts
You normally overlap each pass slightly so a narrow line of grass is not missed. That means the fresh strip cut after the first pass is narrower than the advertised cutting width. The RHS mowing method recommends this slight overlap; the amount needed depends on how accurately you can follow the previous cut.
Here is an illustrative comparison for a 200m² open lawn, assuming 5cm overlap with either mower:
| Cutting width | Fresh width covered per overlapping pass | Approximate straight-line travel |
|---|---|---|
| 40cm | 35cm | 570m |
| 50cm | 45cm | 440m |
The estimate is lawn area divided by the fresh width covered: 200 ÷ 0.35 or 200 ÷ 0.45. It leaves out turns, perimeter work and trips to empty the bag. The 5cm overlap is an example, not a setting every mower needs.
The wider mower covers the open area with less travel. Whether that shortens your whole session depends on how easily you can turn it, keep a comfortable pace and deal with the clippings. A wider cut that repeatedly catches on narrow sections can lose much of its advantage.
Check weight, steps and the space in your shed
Compare the ready-to-use weight of the shortlisted mowers. For cordless models, establish whether the stated weight includes batteries. Think about the movement you will repeat each time: over a threshold, up a step, around stored tools or into a vehicle.
Use the mower’s intended lifting points and handling instructions. If a step would require an uncomfortable lift, choose a more manageable machine or a suitable access arrangement before buying. Test the handle height and your grip on the controls too, where possible.
Self-propelled drive helps move the mower across the lawn, but you still have to steer, park and manoeuvre it. The push versus self-propelled guide explains where drive helps most.
For storage, measure the floor space and the doorway separately. Check the folded length and height, where the collector goes and whether folding the handle is convenient enough for your routine. Stand a mower upright only when its maker permits that storage position; a folding handle alone does not establish this. Leave enough room to get it out without shifting half the shed.
Include collection and battery capacity in the decision
A wider mower can feed more grass into its collector on each pass. Compare the bag capacity and how easily you can remove and empty it, especially if your usual cut produces a lot of material. A large collector can mean fewer stops, but a fuller bag is heavier to carry.
For a cordless mower, check the exact batteries included and how many it needs at once. Some twin-battery machines use both packs together, so a two-battery kit may contain one working set. The cordless mower capacity guide helps you compare the complete setup.
Advertised lawn-area figures need to be considered alongside grass length, density and mowing conditions. Cutting width alone will not tell you whether one charge will finish your garden. Allow for any other jobs that share those batteries, such as trimming the edges after mowing.
Use your measurements to make a shortlist
Write down the total grass area, the narrowest clear opening, any tight turns and the available storage space. Add the job that currently takes the most effort: repeated open-lawn passes, pushing, emptying the bag or moving the mower between areas.
For long runs, compare wider machines that still fit the route and are comfortable to handle. For small sections and awkward access, give compact dimensions more weight. Where both layouts exist, choose around the section you cannot easily work around rather than buying for the largest patch alone.
Then use the best lawn mower guide to compare the actual models, their cutting systems and buying options. Take your measurements with you if you visit a dealer, and try turning and moving a shortlisted mower before committing to it.
