Robot mower vs lawn service: a 5-year cost comparison with every assumption labeled

Every assumption, stated first

This is the list that a cost comparison normally buries. If you disagree with any line, the arithmetic further down is easy to redo with your own figure, which is the point of writing it out.

Two of these are worth arguing with. Season length is a regional fact that nobody publishes nationally, and repairs are excluded because no manufacturer we read publishes a failure rate, a mean service interval, or an out of warranty repair price for any of these machines. Excluding a cost is not the same as claiming it is zero.

• Season: 26 weeks of mowing per year, our assumption, not a published figure.
• Service frequency: one visit per week during the season, so 26 visits per year and 130 over five years. LawnStarter states that once a week is usually plenty during the growing season.
• Service price: two named national sources, used as ranges rather than averaged together (see the service section below).
• Robot price: the list price on the maker's own US store as of 2026-08-06, not a sale price.
• Blades: priced from official store listings read on 2026-08-06, replaced on the published intervals of the makers who publish one.
• Electricity: computed from published battery capacity at the EIA published US average residential rate; see the method in our companion guide.
• Excluded on both sides: repairs, replacement batteries, installation, trimming and edging, resale value, and any price increase over the five years. None of these are published by the parties involved.
• Excluded on the robot side: connectivity fees after the included term. Mammotion includes 3 years of free 4G with the LUBA 3 AWD, Segway includes 3 years with the X350, and Dreame includes 3 years of Link service with the A3 AWD Pro; none publishes what the service costs afterward.

The robot side: hardware

Three machines we publish pages for bracket the realistic range of this decision. The Navimow i110N is the entry point at $1,099 list on navimow.com as of 2026-08-06, sized by Segway at a recommended mowing area of 10,890 sq ft (0.25 acre). The Navimow X350 sits in the middle at $2,799 list on the same date, with a published recommended mowing area of 1.5 acres. The Automower 420 iQ is the top of our bracket at $3,299.99 MSRP, published on husqvarna.com on 2026-08-06 with the buy control marked Out of Stock and no discontinuation notice.

One thing to hold on to before the totals: these are list prices on a single date, and our own record shows discounts around them moving while list prices hold. The X350 carried a $2,239.00 sale price on 2026-07-05 that had ended by 2026-08-06. If you buy in a discount window, subtract it from the totals below rather than from the assumptions. When robot mowers go on sale sets out the two dated observations behind that.

Blades: two published intervals, about five times apart

Blades are the only consumable on these machines with a published price and a published interval, and the makers who publish an interval do not agree. Husqvarna's US support article KA-01722 states that main disc blades typically last 3 to 6 weeks under normal conditions, and that you must replace the screws each time you change blades because reusing them may lead to blades coming loose in operation. Mammotion, on its Endurance Replacement Blades listing, publishes a duty basis instead: flip the blades at 50 hours and replace at 150 hours, footnoted as tested on Zoysia grass.

Work both bases against the same machine and the spread is obvious. The X350 has a published 6 blade cutting disk, and Segway's Blade Assembly Plus pack, $23.99 on navimow.com on 2026-08-06, contains 12 blades, enough for two full changes of that disc on the blade count alone; the listing does not state whether mounting screws are included, and Segway's own maintenance guidance is to replace screws together with blades, so any screw cost is an unpriced line. On Husqvarna's 3 to 6 week interval, a 26 week season needs 4 to 9 changes, which is 2 to 5 packs, or $47.98 to $119.95 per season and $239.90 to $599.75 over five years. On Mammotion's 150 hour basis, with the X350's published 200 minute Full Charge Mowing Time and an assumed three charges per week, 150 hours arrives at about week 15, so the season needs about two sets, one pack, or about $24 per season and $120 over five years. Segway's own 100 to 150 hour consumer maintenance blog figure lands in the same neighborhood: a set every 10 to 15 weeks on these assumptions, about one to two packs per season, or roughly $24 to $48 per season and $120 to $240 over five years.

We are not going to adjudicate that. Blade steel, disc geometry and grass species all differ, each figure is a maker's instruction for its own hardware, and Segway's own published guidance is itself a spread: 80 hours on a support page labeled for its H series, every 1 to 2 months in its support answers, and 100 to 150 hours on its consumer maintenance blog, three figures its own channels do not reconcile. What the spread does tell you is that anyone quoting a single national blade cost per year is contradicting one of these two manufacturers. The mechanics of the job itself are covered in robot mower blade replacement.

• Segway Blade Assembly Plus: $23.99, 12 blades, screw contents not stated on the listing, navimow.com, 2026-08-06.
• Mammotion Endurance Replacement Blades: $49.00 for a 24 piece pack, us.mammotion.com, 2026-08-06.
• Husqvarna Endurance Blades: published in 6 piece (SKU 595 08 44-11) and 45 piece (SKU 595 08 44-12) packs, both listed as fitting the Automower 420 iQ; no price rendered on the US product page when read on 2026-08-06.
• Husqvarna published interval: main disc blades typically 3 to 6 weeks, EdgeCut disc blades 9 to 12 weeks, new screws every change (US support KA-01722).
• Mammotion published interval: flip at 50 hours, replace at 150 hours, tested on Zoysia grass (product listing).
• Blade allowance used below for the X350: $240 to $600 over five years, from the Husqvarna interval applied to Segway's own $23.99 pack.

Electricity: small enough to check, not small enough to skip

Electricity is the line most comparisons hand-wave. It can be computed, but only for the machines whose makers publish both battery capacity and voltage, and that is four of the eleven mowers we publish pages for. At the EIA published US average residential price of 18.44 cents per kWh for May 2026 (Electric Power Monthly, released July 23, 2026), a full charge costs between about 1.3 cents and 5.5 cents on those four machines, and a season of charging costs between about $0.69 and $13.85 depending on how many charges a week you assume.

Neither the X350 nor the 420 iQ is in that computable set. Segway publishes a 10 Ah battery for the X350 with no voltage; Husqvarna publishes a 5 Ah Li-Ion battery and a 4.2 A charging current for the 420 iQ, also with no voltage. Amp hours without volts cannot be converted to watt hours, so for these two machines the electricity line is bracketed from the machines that do publish, not computed from their own specs. In a five year total that is worth at most about $70, which is inside the rounding error of a single service visit at Angi's average price. The full method, model by model, is in what a robot mower adds to your electric bill.

The service side: two publishers, about two times apart

There is no government statistic for what a mowing visit costs, so the honest thing is to name the publishers and show that they disagree. LawnStarter's mowing cost page, last modified 2026-08-04, publishes $43 to $70 per visit with an average of $56, and breaks it down by lawn size: $41 to $61 up to 1/4 acre, $49 to $69 for 1/4 to 1/2 acre, $59 to $114 for 1/2 to 1 acre, and $99 to $264 for 1 to 2 acres. It also publishes $32 to $68 per hour, or $0.01 to $0.06 per square foot.

Angi's lawn mowing cost page, dated March 17, 2026 and titled with 2026 data, publishes a national average of $123 per visit with a range of $49 to $203. The two low ends are close, $41 to $43 against $49. The averages are not: $56 against $123, a factor of about 2.2. We do not know which sampling method is closer to your zip code, and neither publisher's average is a measurement we made, so this guide carries both rather than splitting the difference.

For contrast, one manufacturer publishes its own version of this comparison. Segway's Navimow Academy post dated March 18, 2026 assumes a lawn service charging $80 per weekly visit on a quarter acre property and totals $12,000 over five years, against about $1,624 for a Navimow i210 AWD including electricity, a saving it puts at $10,376. Two things to note before using that number: $12,000 at $80 a visit implies 150 visits, or 30 visits a year rather than our 26, and the i210 AWD is not a model we publish a page for. Their per visit assumption sits above LawnStarter's published range and well below Angi's average.

Five year totals

At 130 visits, the service side spans $5,330 at LawnStarter's low quarter acre figure of $41 per visit to $26,390 at Angi's high figure of $203. Using each publisher's headline average, it is $7,280 (LawnStarter, $56) or $15,990 (Angi, $123). That spread is the single largest uncertainty in this whole page, and it comes entirely from the service side, not from the machines.

The robot side is narrower because two of its three lines are published prices rather than surveys. The X350 is the fully worked example: $2,799 hardware, $120 to $600 of blades over five years across the published intervals (Segway's own 100 to 150 hour figure at the low end, Husqvarna's 3 to 6 week interval at the high end), and an electricity line bracketed at $3 to $70, for a five year total of roughly $2,920 to $3,470. The i110N, borrowing the same blade bracket because Segway does not publish a blade count per disc for it, lands at roughly $1,220 to $1,770. The 420 iQ starts at $3,299.99 with a blade line we cannot price, since no price rendered on Husqvarna's US blade pages, though its product page does list a promotion of one year of free blades and Husqvarna backs the mower with a 4 year US and Canada warranty.

On these assumptions every service scenario we could source costs more over five years than every robot total we could fully compute, and the cheapest service case, $5,330, still exceeds the highest fully computed machine total, the X350 at about $3,470, by more than $1,800. That result is robust to the service price disagreement, but it is not robust to a repair. Nobody publishes repair costs, which is exactly why the next section exists.

• Service, 130 visits: $5,330 to $7,930 (LawnStarter, up to 1/4 acre, $41 to $61).
• Service, 130 visits: $6,370 to $8,970 (LawnStarter, 1/4 to 1/2 acre, $49 to $69).
• Service, 130 visits: $7,280 at LawnStarter's $56 average; $15,990 at Angi's $123 average.
• Service, 130 visits: $6,370 to $26,390 across Angi's full published range of $49 to $203.
• Robot, Navimow i110N: about $1,340 to $1,770 (hardware $1,099 as of 2026-08-06, blades $240 to $600, electricity $3 to $70).
• Robot, Navimow X350: about $2,920 to $3,470 (hardware $2,799 as of 2026-08-06, blades $120 to $600 across the published intervals, electricity $3 to $70).
• Robot, Automower 420 iQ: at least $3,299.99 hardware as of 2026-08-06, plus a blade line with no published US price.

Where the record has gaps

The largest hole is repairs, and it is a hole on both sides. No manufacturer behind these machines publishes a failure rate, an expected service life, a replacement battery price, or an out of warranty repair cost, and no service publisher we read prices the risk that a crew damages something. Warranty terms are published and they differ sharply, 3 years on the i110N and X350 mowers with 2 years on the X350 battery pack and adapters, and 4 years on the Automower 420 iQ unit with a separate 3 year battery warranty, so the exposure after year three is not the same across brands. How long these machines actually last is its own question, and the published record on it is thin: see how long do robot mowers last.

The second hole is scope. A mowing service visit and a robot mower are not the same product. The published service figures we used are for mowing; trimming, edging, blowing and cleanup are priced separately by both publishers, and a robot mower does none of them. If your current quote includes those, you are comparing a smaller number on the service side than the one you actually pay, and the machine will not eliminate the trimmer.

The third is that we have not tested any of this. Every machine figure here is a manufacturer's published claim with its basis attached, every service figure is a named publisher's survey with its date attached, and the season length is our own stated assumption. If the honest version of this question is whether the machine is worth owning at all rather than which is cheaper on a spreadsheet, that is the subject of are robot mowers worth it.