How many Google reviews do you need for the map pack? Eight trades, the same 22 cities

Every local trade gets handed the same advice with a different number in it. Get to 100 reviews. Get to 500. The number is usually round, it rarely says which trade or which city it was measured in, and the owner hearing it has no way to check whether it was measured at all.

Since late September we have captured the Google Maps top 20 for eight trades in one list of 22 US cities, 11 large metros and 11 small cities: roofing contractors, house cleaning services, garage door repair, locksmiths, dentists, moving companies, hair salons and physical therapy. This article puts the eight shipped datasets side by side without spending a search: 3,352 results, 3,031 businesses after each study’s exclusions, 2,995 with a review count, in 176 trade-by-city lists. The belief under test is that a single review number exists. It does not, the market size moves it more than the trade does, and one rule holds in all eight trades anyway.

Find your row

The median listing in the top 20 runs from 13 reviews (house cleaning, small cities) to 621 (dentists, large metros). Pooled across everything it is 141, which describes no list anyone competes in, so here are the 16 rows instead. The floor is the least reviewed business in each city’s top three, reported as the median across the 11 cities. The multiple is the median top-three listing divided by the median listing in its own city.

Trade	Market	Median listing	Top three	Floor	Top three ÷ city median	Top-three slots under 100	Chain or brand share
Roofing	Metros	153	246	134	1.5	4 of 33	8%
Roofing	Small cities	33	119	69	4.1	13 of 33	6%
House cleaning	Metros	148	387	104	1.58	6 of 33	29%
House cleaning	Small cities	13	57	43	3.95	20 of 29	4%
Garage door repair	Metros	199	1,131	401	4.37	5 of 33	21%
Garage door repair	Small cities	36	87	48	2.6	17 of 33	12%
Locksmiths	Metros	235	841	370	3.04	0 of 33	3%
Locksmiths	Small cities	126	205	97	1.13	6 of 29	3%
Dentists	Metros	621	851	495	1.18	0 of 33	5%
Dentists	Small cities	364	876	465	2.22	0 of 33	7%
Moving	Metros	500	1,395	807	3.31	1 of 33	29%
Moving	Small cities	47	132	48	3.14	13 of 32	13%
Hair salons	Metros	290	561	244	1.69	1 of 33	1%
Hair salons	Small cities	79	170	134	2.23	8 of 33	7%
Physical therapy	Metros	114	171	106	1.46	5 of 32	47%
Physical therapy	Small cities	19	114	35	3.47	15 of 33	44%

Read your row, then do the one-minute version in your own city: search your trade plus your city, read the twenty review counts, take the middle one, and multiply by the figure in the sixth column. That is what the top three carry where you are.

The market moves the number more than the trade does

Within the metros, the median listing runs from 114 (physical therapy) to 621 (dentists), a spread of 5.45 times. Within the small cities it runs from 13 to 364, a spread of 28 times. Between the two market sizes, inside one trade, the ratio is 1.71 for dentists and 1.87 for locksmiths at the low end, then 3.67 for hair salons, 4.64 for roofing, 5.53 for garage doors and 6 for physical therapy, and 10.64 for moving and 11.38 for house cleaning at the top. A metro house cleaner’s median competitor has 148 reviews; a small-city one has 13.

So a benchmark quoted without a market size is wrong for most readers in either direction. Pooled across all eight trades, the metro top 20 reads 545 reviews at positions 1 to 3, 307 at 4 to 7, 230 at 8 to 12 and 153 at 13 to 20. The small-city top 20 reads 164, 61, 37 and 28. A small-city owner holding 60 reviews is above the median of their list in five of the eight trades. A metro owner holding 60 is below it in all eight.

The hundred-review door, tested 176 times

The belief that 100 reviews is the price of a top-three spot can be tested directly: in how many of the 176 trade-by-city lists does the least reviewed business in the top three have fewer than 100? The answer is 76 of 176, 43 percent. The split is the finding. In the metros it is 18 of 88 lists, 20 percent; in the small cities 58 of 88, 66 percent. Under 50 reviews: 9 of 88 metro lists and 34 of 88 small-city lists. The median floor is 238 reviews in a metro and 71 in a small city.

Two trades have no such door at all. Dentists had no top-three listing under 100 reviews in any of the 22 cities, and the metro locksmith lists had none either. At the other end, 20 of 29 small-city house cleaning top-three slots were held by a business with fewer than 100 reviews, and 17 of 33 small-city garage door slots.

Counted by slot rather than by list, 22 of the 263 metro top-three listings have fewer than 100 reviews, 8 percent, against 92 of 255 in the small cities, 36 percent. In a small city the question is not whether a business with 40 reviews can reach the top three, because in two of every three lists one already has.

The rule that travels, and the one that does not

Two earlier studies proposed that the top three carry about three times the city’s median listing. Across eight trades the pooled multiple is 2.13: 1.83 in metros and 2.43 in small cities. Inside the trades it runs from 1.18 (dentists, metros) to 4.37 (garage doors, metros), and the small-city multiple is higher than the metro one in five of the eight trades, with locksmiths and garage doors running the other way and moving nearly flat. Multiply by three is a fair middle guess and a poor rule; the sixth column is the rule.

What does travel is the shape. In all eight trades, in both market sizes, review volume orders the list and rating does not. The rank correlation between position and review count is negative and significant in 8 of 8 trades pooled, from -0.206 (moving) to -0.359 (dentists); in the metros it runs from -0.228 to -0.488, and in the small cities from -0.379 to -0.537, stronger where the counts are smaller. The correlation between position and rating is not significant in any of the eight trades pooled, in none of the eight in the metros, and in one of the eight in the small cities (house cleaning, 0.207, and the sign runs toward lower positions for higher ratings). The median rating of the top three is 4.9 in both market sizes, and so is the median rating of positions 13 to 20.

Rating is a floor and it is a high one. The median rating by trade is 4.8 (locksmiths, moving, hair salons), 4.9 (roofing, house cleaning, garage doors, dentists) or 5.0 (physical therapy). The share of listings at a flat 5.0 runs from 12 percent of hair salons to 52 percent of physical therapy clinics, and rises in the small cities, 33 percent against 24 in the metros, because a 5.0 is mostly a small count: more reviews go with a slightly lower rating in both market sizes (rank correlation -0.106 in metros, -0.104 in small cities). A business below 4.5 is rare in a metro list, 5 percent, and three times as common in a small-city list, 16 percent.

One more belief dies in every trade: that position 1 is the most reviewed business in town. It was in 48 of 175 lists, 27 percent; 17 of 88 in the metros and 31 of 87 in the small cities. By trade the count ran from 4 of 22 cities (roofing) to 9 of 22 (locksmiths).

Who you are competing with differs by trade

The share of the top 20 tagged as a chain, franchise or organization runs from 3 percent (locksmiths) to 46 percent (physical therapy, where the tag also covers hospital systems and physician groups). Moving sits at 23 percent, house cleaning and garage doors at 18, roofing at 7, dentists at 6, hair salons at 4. In the top three the range is wider: 2 percent of dentist slots and 3 percent of salon slots, against 42 percent of physical therapy slots and 29 percent in moving, house cleaning and garage doors. In the metros no salon top-three slot was a chain and half of the physical therapy slots were.

Limits

This is a roll-up of eight snapshots, not one capture. The searches ran on eight days between September 29 and October 14, 2026, US time, on different weekdays and hours; two of them, dentists on a Thursday morning and hair salons on a Monday morning, were the baselines of panel studies that later showed a closed listing moves about three places on the day it is closed. That changes who sits where inside a list on the day, not how many reviews the listings carry.

Each row is a trade’s own screen and its own tag, so the chain share is only loosely comparable across trades: an organization in physical therapy (a health system) has no counterpart in a locksmith list. The small-city rows for locksmiths rest on 63 listings in 11 cities and for garage doors on 115, because Google returned short lists there once kiosks and door suppliers were removed; those rows carry wider error than the others. 36 listings showed no review count and are missing, not zero. 321 results were excluded by the eight studies with their reasons kept in the dataset, the largest groups being 58 automated key kiosks, 15 trucking companies, 14 self-storage facilities, 13 janitorial services and 13 door suppliers.

Every listing measured already ranks in the top 20, so nothing here says what separates a listed business from an unlisted one, only how the listed ones are arranged. Correlation is not cause: the businesses that rank higher could collect more reviews because they are busier, older or better placed, and we measured none of that. Review counts and ratings are as Google displayed them on the day of each capture.