Lawn Mowing Calculator - Time, Fuel and Season Cost

How long does mowing a 300 m2 lawn actually take - and what does a full season cost?

A 300 m2 lawn takes roughly 45 minutes per mow with a standard push mower. Mow it weekly from April through October and you are looking at 30 sessions and 22.5 hours of total mowing time per year. The electricity bill for an electric mower? About $1.69 for the entire season at $0.15/kWh. A gas mower burns through $20.25 in fuel. A robotic mower does it for $2.52 in electricity - but costs $500-2,500 upfront. This calculator runs the numbers for your specific lawn.

How to use the lawn mowing calculator - step by step

Lawn area (m2) - measure your lawn or estimate from your property plan. A typical suburban lawn is 150-400 m2. The calculator assumes 15 minutes per 100 m2 of mowing time.
Mower type - choose electric (1.5 kW corded or battery), gas (petrol push mower at 0.9 L/hour) or robotic (automatic, 8 kWh/month per 100 m2). Each has different running costs.
Mowing frequency - weekly gives 30 mows per season, every 2 weeks gives 15, monthly gives 7. The mowing season runs April through October (7 months).
Electricity price - for electric and robotic mowers. US average: $0.12-0.16/kWh, UK: $0.28-0.34/kWh, EU: $0.20-0.35/kWh.
Gasoline price - for gas mowers only. US average: $0.85-1.10/L, EU: $1.50-2.00/L.
Read results - time per mow, mows per season, total energy consumption and the full season cost in dollars.

Mower comparison table

All figures based on a 300 m2 lawn, mowed weekly (30 times per season), at US average energy prices.

Parameter	Electric	Gas	Robotic
Purchase price	$100-400	$200-800	$500-2,500
Power	1,000-1,800 W	2-6 HP	20-30 W
Speed	200-400 m2/hr	300-600 m2/hr	automatic
Season cost (300 m2)	$1.69	$20.25	$2.52
Your time per mow	45 min	30-45 min	0 min
Max lawn size	up to 500 m2	unlimited	500-5,000 m2
Noise level	75-85 dB	90-100 dB	55-65 dB

Season cost by lawn size

Lawn area	Electric ($0.15/kWh)	Gas ($1.00/L)	Robot ($0.15/kWh)	Time per mow
100 m2	$0.56	$6.75	$0.84	15 min
200 m2	$1.13	$13.50	$1.68	30 min
300 m2	$1.69	$20.25	$2.52	45 min
500 m2	$2.81	$33.75	$4.20	1 hr 15 min
1,000 m2	$5.63	$67.50	$8.40	2 hrs 30 min

Weekly mowing (30 times/season, April-October). Gas mower: 0.9 L/hour. Electric: 1.5 kWh/hour. Robot: 8 kWh/month per 100 m2.

Practical examples

Small front lawn, 80 m2, electric, every 2 weeks: 12 min per mow, 15 mows, 4.5 kWh total. Season cost: $0.68.

Suburban yard, 250 m2, gas, weekly: 38 min per mow, 30 mows, 17.1 L gasoline. Season cost: $17.10 (+ ~$8 engine oil).

Family garden, 400 m2, electric, weekly: 60 min per mow, 30 mows, 45 kWh total. Season cost: $6.75. Total mowing time: 30 hours per year.

Large property, 800 m2, robot: 0 min per mow, fully automatic. 44.8 kWh per month, 313.6 kWh per season. Season cost: $47.04. But zero time spent.

Minimal care, 300 m2, gas, monthly: 45 min per mow, 7 mows, 4.7 L gasoline. Season cost: $4.73. Grass will be longer between cuts.

Common mistakes when choosing a mower

Mistake 1: Buying a gas mower for a small lawn. For lawns under 300 m2, an electric mower is cheaper to buy, cheaper to run and quieter. Gas makes sense above 500 m2 or for uneven terrain without power outlets nearby.

Mistake 2: Ignoring time cost. A 300 m2 lawn mowed weekly takes 22.5 hours per season. At $15/hour, that is $337 worth of your time. A $1,200 robot pays for itself in under 4 seasons by time value alone.

Mistake 3: Mowing too short. Cutting below 4 cm weakens roots and invites weeds. Never remove more than 1/3 of the grass height in a single mow. Higher grass = deeper roots = healthier lawn.

FAQ

How much electricity does an electric mower use per session?

A typical corded electric mower draws 1.5 kW. For a 300 m2 lawn (45 minutes of mowing), that is about 1.13 kWh per session. At $0.15/kWh, one mow costs roughly $0.17. A full season of weekly mowing costs $1.69.

How much gasoline does a gas mower use per hour?

A standard push gas mower consumes about 0.9 liters per hour. A self-propelled model uses 1.0-1.2 L/hr. A riding mower burns 2-4 L/hr. For a 300 m2 lawn (45 min): 0.68 L per mow.

Is a robotic mower worth the investment?

In running costs alone, a robot is comparable to an electric mower. The real value is time savings. A 300 m2 lawn mowed weekly takes 22.5 hours per season. If your time is worth $15/hour, a $1,200 robot pays for itself in under 4 seasons. For large lawns (500+ m2), the payback is even faster.

How often should I mow my lawn?

Weekly during peak growth (May-July). Every 2 weeks is fine for low-maintenance lawns or during slower growth (April, August-October). Monthly works only for rough areas or meadow-style gardens. The 1/3 rule: never cut more than one-third of the blade height at once.

How long does it take to mow 100 m2?

With a standard push mower (40 cm cutting width, walking pace): about 15 minutes per 100 m2. This includes overlapping passes and turning. So a 200 m2 lawn takes roughly 30 minutes, 500 m2 takes about 75 minutes, and 1,000 m2 takes about 2.5 hours.

Electric vs gas mower - which is cheaper overall?

For running costs: electric wins easily. A season costs $1.69 (electric) vs $20.25 (gas) for a 300 m2 lawn. Add maintenance: gas mowers need oil changes ($8-15/year), spark plugs ($5) and air filters ($8). Over 10 years, a $300 electric mower saves $400-600 compared to a $400 gas mower.

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