Adizero Boston v12
Width options: standard (Men's) / standard (Women's)
Imported family signal
28 of 37 runners said this shoe fit true to size.
Fit Notes
Runs true to size. Narrow fit — wide feet size up.
Sizing vs. popular reference shoes
| If you wear | Length | Width | Toebox | Reports |
|---|---|---|---|---|
Adidas Adizero Adios Pro 3 (Men's) 10.5100% 1 of 1 runners landed on 10.5 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 10.5-10.5 |
Adidas Adizero Adios Pro 3 (Women's) 8.0100% 1 of 1 runners landed on 8.0 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 8-8 |
Adidas Adizero Boston 12 (Men's) US M 11.5100% 1 of 1 runners landed on US M 11.5 (0.5 weighted). | True to size | True to width | Roomy toebox | Early reportsEarly Based on 1 reportUS 11.5-11.5 |
Adidas Adizero Evo SL (Men's) 10.5100% 1 of 1 runners landed on 10.5 (0.5 weighted). | True to size | Slightly narrow | Snug toebox | Early reportsEarly Based on 1 reportUS 10.5-10.5 |
Adidas Adizero Evo SL (Women's) US 8.5100% 1 of 1 runners landed on US 8.5 (0.5 weighted). | True to size | Slightly narrow | Good room | Early reportsEarly Based on 1 reportUS 8.5-8.5 |
Adidas Adizero SL 2 (Men's) 12.5100% 1 of 1 runners landed on 12.5 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 12.5-12.5 |
Adidas Adizero Takumi Sen 8 (Men's) US8/UK7.5/EU41 1/3100% 1 of 1 runners landed on US8/UK7.5/EU41 1/3 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 87.54113-87.54113 |
Asics GT-2000 13 (Women's) 9100% 1 of 1 runners landed on 9 (0.5 weighted). | True to size | Slightly narrow | Good room | Early reportsEarly Based on 1 reportUS 9-9 |
Asics Superblast 1 (Women's) US 8.5100% 1 of 1 runners landed on US 8.5 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 8.5-8.5 |
Asics Superblast 2 (Men's) 10.5100% 1 of 1 runners landed on 10.5 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 10.5-10.5 |
Asics Superblast 2 (Women's) US 8.5100% 1 of 1 runners landed on US 8.5 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 8.5-8.5 |
Brooks Adrenaline GTS 24 (Women's) 9100% 1 of 1 runners landed on 9 (0.5 weighted). | True to size | Slightly wide | Good room | Early reportsEarly Based on 1 reportUS 9-9 |
Hoka Mach 6 (Men's) 10.5100% 1 of 1 runners landed on 10.5 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 10.5-10.5 |
New Balance Fresh Foam 1080 13 (Men's) 10.5100% 1 of 1 runners landed on 10.5 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 10.5-10.5 |
New Balance Fresh Foam 1080 13 (Women's) 10.5100% 1 of 1 runners landed on 10.5 (0.5 weighted). | True to size | Slightly narrow | Good room | Early reportsEarly Based on 1 reportUS 10.5-10.5 |
New Balance Fresh Foam 860 13 (Women's) 10.5100% 1 of 1 runners landed on 10.5 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 10.5-10.5 |
New Balance FuelCell Rebel 3 (Women's) 11.5100% 1 of 1 runners landed on 11.5 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 11.5-11.5 |
Nike Alphafly 3 (Men's) 10.5100% 1 of 1 runners landed on 10.5 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 10.5-10.5 |
Nike Alphafly 3 (Women's) US 8.5100% 1 of 1 runners landed on US 8.5 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 8.5-8.5 |
Nike Pegasus 41 (Men's) 10US100% 1 of 1 runners landed on 10US (0.5 weighted). | True to size | Slightly wide | Roomy toebox | Early reportsEarly Based on 1 reportUS 10-10 |
Nike Pegasus 42 (Women's) 8.5100% 1 of 1 runners landed on 8.5 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 8.5-8.5 |
Nike Vaporfly 2 (Men's) 10.5100% 1 of 1 runners landed on 10.5 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 10.5-10.5 |
Puma Deviate Nitro 2 (Men's) 10.5100% 1 of 1 runners landed on 10.5 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 10.5-10.5 |
Puma Fast-R 2 (Men's) 10.5100% 1 of 1 runners landed on 10.5 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 10.5-10.5 |
Saucony Endorphin Speed 2 (Women's) 10100% 1 of 1 runners landed on 10 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 10-10 |
Saucony Endorphin Speed 3 (Men's) 10.5100% 1 of 1 runners landed on 10.5 (0.5 weighted). | True to size | True to width | Good room | Early reportsEarly Based on 1 reportUS 10.5-10.5 |
Saucony Kinvara 14 (Women's) US 9100% 1 of 1 runners landed on US 9 (0.5 weighted). | True to size | Slightly narrow | Snug toebox | Early reportsEarly Based on 1 reportUS 9-9 |
Saucony Triumph 20 (Women's) 11.5100% 1 of 1 runners landed on 11.5 (0.5 weighted). | True to size | Slightly wide | Good room | Early reportsEarly Based on 1 reportUS 11.5-11.5 |
Adidas Adizero SL 2 (Women's) 9.5100% 1 of 1 runners landed on 9.5 (0.4 weighted). | Consider sizing up 0.5 | True to width | Good room | Early reportsEarly Based on 1 reportUS 9.5-9.5 |
Asics Gel-Cumulus 26 (Women's) 11100% 1 of 1 runners landed on 11 (0.4 weighted). | Some go half size down | True to width | Good room | Early reportsEarly Based on 1 reportUS 11-11 |
Nike Vaporfly 2 (Women's) 12100% 1 of 1 runners landed on 12 (0.4 weighted). | Some go half size down | True to width | Good room | Early reportsEarly Based on 1 reportUS 12-12 |
Saucony Endorphin Pro 2 (Men's) 12100% 1 of 1 runners landed on 12 (0.4 weighted). | Some go half size down | Slightly wide | Good room | Early reportsEarly Based on 1 reportUS 12-12 |
Saucony Endorphin Speed 4 (Men's) 12100% 1 of 1 runners landed on 12 (0.4 weighted). | Some go half size down | Slightly wide | Good room | Early reportsEarly Based on 1 reportUS 12-12 |
Saucony Endorphin Speed 4 (Women's) 8.5100% 1 of 1 runners landed on 8.5 (0.4 weighted). | Consider sizing up 0.5 | True to width | Good room | Early reportsEarly Based on 1 reportUS 8.5-8.5 |
Adidas Adizero Takumi Sen 8 (Women's) 9100% 1 of 1 runners landed on 9 (0.4 weighted). | Size down 0.5 | True to width | Good room | Early reportsEarly Based on 1 reportUS 9-9 |
Saucony Endorphin Speed 3 (Women's) 5.5/22.5cm100% 1 of 1 runners landed on 5.5/22.5cm (0.4 weighted). | Size down 0.5 | True to width | Good room | Early reportsEarly Based on 1 reportUS 5.522-5.522 |
Adidas Adizero Takumi Sen 9 (Women's) unknown100% 1 of 1 runners landed on unknown (0.4 weighted). | Size down 0.5 | True to width | Good room | Early reportsEarly Based on 1 report |
1 of 1 runners landed on 10.5 (0.5 weighted).
1 of 1 runners landed on 8.0 (0.5 weighted).
1 of 1 runners landed on US M 11.5 (0.5 weighted).
1 of 1 runners landed on 10.5 (0.5 weighted).
1 of 1 runners landed on US 8.5 (0.5 weighted).
1 of 1 runners landed on 12.5 (0.5 weighted).
1 of 1 runners landed on US8/UK7.5/EU41 1/3 (0.5 weighted).
1 of 1 runners landed on 9 (0.5 weighted).
1 of 1 runners landed on US 8.5 (0.5 weighted).
1 of 1 runners landed on 10.5 (0.5 weighted).
1 of 1 runners landed on US 8.5 (0.5 weighted).
1 of 1 runners landed on 9 (0.5 weighted).
1 of 1 runners landed on 10.5 (0.5 weighted).
1 of 1 runners landed on 10.5 (0.5 weighted).
1 of 1 runners landed on 10.5 (0.5 weighted).
1 of 1 runners landed on 10.5 (0.5 weighted).
1 of 1 runners landed on 11.5 (0.5 weighted).
1 of 1 runners landed on 10.5 (0.5 weighted).
1 of 1 runners landed on US 8.5 (0.5 weighted).
1 of 1 runners landed on 10US (0.5 weighted).
1 of 1 runners landed on 8.5 (0.5 weighted).
1 of 1 runners landed on 10.5 (0.5 weighted).
1 of 1 runners landed on 10.5 (0.5 weighted).
1 of 1 runners landed on 10.5 (0.5 weighted).
1 of 1 runners landed on 10 (0.5 weighted).
1 of 1 runners landed on 10.5 (0.5 weighted).
1 of 1 runners landed on US 9 (0.5 weighted).
1 of 1 runners landed on 11.5 (0.5 weighted).
1 of 1 runners landed on 9.5 (0.4 weighted).
1 of 1 runners landed on 11 (0.4 weighted).
1 of 1 runners landed on 12 (0.4 weighted).
1 of 1 runners landed on 12 (0.4 weighted).
1 of 1 runners landed on 12 (0.4 weighted).
1 of 1 runners landed on 8.5 (0.4 weighted).
1 of 1 runners landed on 9 (0.4 weighted).
1 of 1 runners landed on 5.5/22.5cm (0.4 weighted).
1 of 1 runners landed on unknown (0.4 weighted).
Community reports
Across the full report set, this many called the shoe true to size.
Reports with extra written context about what runners actually felt.
Signals for hotspots, blisters, or other pain points across the full report set.
| Came from | Bought | Verdict | Runner note | Issues | When |
|---|---|---|---|---|---|
Saucony Endorphin Pro 2 (Men's) Size 12 | 12 | Slightly longSlightly wide | Boston 12 is roomier than Endorphin Pro 2 at same size | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/16x7p6w/boston_12_fit_check/] | No issues | Mar 2026 |
Saucony Endorphin Speed 4 (Men's) Size 12 | 12 | Slightly longSlightly wide | Boston 12 is roomier than Endorphin Speed at same size | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/16x7p6w/boston_12_fit_check/] | No issues | Mar 2026 |
Adidas Adizero Boston 12 (Men's) Size US M 12 | US M 11.5 | True to sizeTrue to width | 11.5 had better match to foot shape and dimensions with plenty of toe room; more race day feel in toe-zone than PX1S with no creasing in forefoot | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/162dn9c/adidas_prime_x_2_strung_review/] | No issues | Mar 2026 |
Adidas Adizero SL 2 (Men's) Size 13 | 12.5 | True to sizeTrue to width | sized down from 13 to 12.5 as with all adizero shoes, fit perfectly | [gender: male/explicit] | [source: /r/RunningShoeGeeks/comments/18rl36a/boston_12_first_impression/] | No issues | Mar 2026 |
Nike Alphafly 3 (Men's) Size 11 | 10.5 | True to sizeTrue to width | Alphafly 3 sized up full size (11) vs Boston 13 at half-size up (10.5) from base size 10 2E | [ambiguity: Extracted from poster's fit reference list showing different sizing strategies for different shoes] | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/1lt3vo5/thoughts_on_the_boston_13_as_a_long_run_shoe_for/] | No issues | Mar 2026 |
Nike Vaporfly 2 (Men's) Size 11 | 10.5 | True to sizeTrue to width | Vaporfly 2 sized up full size (11) vs Boston 13 at half-size up (10.5) from base size 10 2E | [ambiguity: Extracted from poster's fit reference list showing different sizing strategies for different shoes] | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/1lt3vo5/thoughts_on_the_boston_13_as_a_long_run_shoe_for/] | No issues | Mar 2026 |
New Balance Fresh Foam 1080 13 (Men's) Size 10.5 | 10.5 | True to sizeTrue to width | Both shoes sized up half-size from base size 10 2E | [ambiguity: Extracted from poster's fit reference list showing consistent half-size up strategy] | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/1lt3vo5/thoughts_on_the_boston_13_as_a_long_run_shoe_for/] | No issues | Mar 2026 |
Hoka Mach 6 (Men's) Size 10.5 | 10.5 | True to sizeTrue to width | Both shoes sized up half-size from base size 10 2E | [ambiguity: Extracted from poster's fit reference list showing consistent half-size up strategy] | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/1lt3vo5/thoughts_on_the_boston_13_as_a_long_run_shoe_for/] | No issues | Mar 2026 |
Adidas Adizero Adios Pro 3 (Men's) Size 10.5 | 10.5 | True to sizeTrue to width | Both shoes sized up half-size from base size 10 2E | [ambiguity: Extracted from poster's fit reference list showing consistent half-size up strategy] | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/1lt3vo5/thoughts_on_the_boston_13_as_a_long_run_shoe_for/] | No issues | Mar 2026 |
Adidas Adizero Evo SL (Men's) Size 10.5 | 10.5 | True to sizeSlightly narrow | Boston 13 has aggressive toe box taper vs Evo SL, but fit acceptable for 2E feet at half-size up. Less forgiving than Evo SL. | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/1lt3vo5/thoughts_on_the_boston_13_as_a_long_run_shoe_for/] | No issues | Mar 2026 |
Boston 12 is roomier than Endorphin Pro 2 at same size | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/16x7p6w/boston_12_fit_check/]
Boston 12 is roomier than Endorphin Speed at same size | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/16x7p6w/boston_12_fit_check/]
11.5 had better match to foot shape and dimensions with plenty of toe room; more race day feel in toe-zone than PX1S with no creasing in forefoot | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/162dn9c/adidas_prime_x_2_strung_review/]
sized down from 13 to 12.5 as with all adizero shoes, fit perfectly | [gender: male/explicit] | [source: /r/RunningShoeGeeks/comments/18rl36a/boston_12_first_impression/]
Alphafly 3 sized up full size (11) vs Boston 13 at half-size up (10.5) from base size 10 2E | [ambiguity: Extracted from poster's fit reference list showing different sizing strategies for different shoes] | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/1lt3vo5/thoughts_on_the_boston_13_as_a_long_run_shoe_for/]
Vaporfly 2 sized up full size (11) vs Boston 13 at half-size up (10.5) from base size 10 2E | [ambiguity: Extracted from poster's fit reference list showing different sizing strategies for different shoes] | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/1lt3vo5/thoughts_on_the_boston_13_as_a_long_run_shoe_for/]
Both shoes sized up half-size from base size 10 2E | [ambiguity: Extracted from poster's fit reference list showing consistent half-size up strategy] | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/1lt3vo5/thoughts_on_the_boston_13_as_a_long_run_shoe_for/]
Both shoes sized up half-size from base size 10 2E | [ambiguity: Extracted from poster's fit reference list showing consistent half-size up strategy] | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/1lt3vo5/thoughts_on_the_boston_13_as_a_long_run_shoe_for/]
Both shoes sized up half-size from base size 10 2E | [ambiguity: Extracted from poster's fit reference list showing consistent half-size up strategy] | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/1lt3vo5/thoughts_on_the_boston_13_as_a_long_run_shoe_for/]
Boston 13 has aggressive toe box taper vs Evo SL, but fit acceptable for 2E feet at half-size up. Less forgiving than Evo SL. | [gender: male/inferred] | [source: /r/RunningShoeGeeks/comments/1lt3vo5/thoughts_on_the_boston_13_as_a_long_run_shoe_for/]
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