True-to-Size Millimeter Sizing Comparison

Allbirds Tree Runner vs Brooks Addiction Walker 2

Detailed size conversion chart, cavity measurements in millimeters, and crowd-sourced fit advice for choosing your perfect size.

4.7(6,450 reviews)
Fit TendencyTrue to Size
Width ProfileStandard (Medium)
View Full Tree Runner Breakdown
4.1(3,271 reviews)
Fit TendencyTrue to Size
Width ProfileStandard (Medium)
View Full Addiction Walker 2 Breakdown
Fit Verdict

True to Size Comparison

Both shoes share a very similar length profile. We recommend ordering your standard size in both.

Length Delta-0.24 mm
Width Delta-0.12 mm

Interactive Size Converter

Select what size you wear in the Tree Runner to see your calculated size in the Addiction Walker 2.

Recommended Size in Brooks Addiction Walker 2
US 8.597% Match

Internal shoe cavity difference: -0.2 mm (snugger)

Complete Size Conversion Matrix

Direct millimeter-calibrated mapping comparing all available sizes between both shoes.

Tree Runner (US)Internal CavityAddiction Walker 2 EquivalentMatch AccuracyFit Difference
US 3.5240 mmUS 70%+26.8 mm
US 4243 mmUS 70%+23.8 mm
US 4.5247 mmUS 70%+19.8 mm
US 5250 mmUS 70%+16.8 mm
US 5.5253 mmUS 70%+13.8 mm
US 6257 mmUS 70%+9.8 mm
US 6.5260 mmUS 720%+6.8 mm
US 7267 mmUS 797%-0.2 mm
US 7.5270 mmUS 7.597%-0.2 mm
US 8273 mmUS 897%-0.2 mm
US 8.5277 mmUS 8.597%-0.2 mm
US 9280 mmUS 997%-0.2 mm
US 9.5283 mmUS 9.597%-0.2 mm
US 10287 mmUS 1097%-0.2 mm
US 10.5290 mmUS 10.597%-0.2 mm
US 11293 mmUS 1197%-0.2 mm
US 11.5297 mmUS 11.597%-0.2 mm
US 12300 mmUS 1297%-0.2 mm
US 12.5303 mmUS 12.597%-0.2 mm
US 13307 mmUS 1397%-0.2 mm
US 14313 mmUS 1497%-0.2 mm

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Frequently Asked Questions

How does the Tree Runner size compare to the Addiction Walker 2?

Both shoes share a very similar length profile. We recommend ordering your standard size in both. The Tree Runner has an internal fit offset of -0.2mm compared to -0.44mm for the Addiction Walker 2.

Do these shoes fit wide feet comfortably?

The Tree Runner has a snug/narrow width profile, while the Addiction Walker 2 is snug/narrow.