True-to-Size Millimeter Sizing Comparison

Allbirds Tree Runner vs New Balance Fresh Foam Arishi v4

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
4.3(1,394 reviews)
Fit TendencyTrue to Size
Width ProfileStandard (Medium)
View Full Fresh Foam Arishi v4 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-0.28 mm
Width Delta+0.09 mm

Interactive Size Converter

Select what size you wear in the Tree Runner to see your calculated size in the Fresh Foam Arishi v4.

Recommended Size in New Balance Fresh Foam Arishi v4
US 1056% Match

Internal shoe cavity difference: +3.7 mm (slightly roomier)

Alternate option if between sizes: US 9.5 (85% match)

Complete Size Conversion Matrix

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

Tree Runner (US)Internal CavityFresh Foam Arishi v4 EquivalentMatch AccuracyFit Difference
US 3.5240 mmUS 691%+0.7 mm
US 4243 mmUS 6.568%+2.7 mm
US 4.5247 mmUS 756%+3.7 mm
US 5250 mmUS 791%+0.7 mm
US 5.5253 mmUS 7.568%+2.7 mm
US 6257 mmUS 856%+3.7 mm
US 6.5260 mmUS 891%+0.7 mm
US 7267 mmUS 956%+3.7 mm
US 7.5270 mmUS 991%+0.7 mm
US 8273 mmUS 9.568%+2.7 mm
US 8.5277 mmUS 1056%+3.7 mm
US 9280 mmUS 1091%+0.7 mm
US 9.5283 mmUS 10.568%+2.7 mm
US 10287 mmUS 1156%+3.7 mm
US 10.5290 mmUS 1191%+0.7 mm
US 11293 mmUS 11.568%+2.7 mm
US 11.5297 mmUS 1256%+3.7 mm
US 12300 mmUS 1291%+0.7 mm
US 12.5303 mmUS 12.568%+2.7 mm
US 13307 mmUS 1356%+3.7 mm
US 14313 mmUS 13.568%+2.7 mm

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Frequently Asked Questions

How does the Tree Runner size compare to the Fresh Foam Arishi v4?

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 -0.48mm for the Fresh Foam Arishi v4.

Do these shoes fit wide feet comfortably?

The Tree Runner has a snug/narrow width profile, while the Fresh Foam Arishi v4 is snug/narrow.