True-to-Size Millimeter Sizing Comparison

Ariat Terrain H2O vs The North Face THERMOBALL Traction Bootie

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

5.0(6,022 reviews)
Fit TendencyTrue to Size
Width ProfileStandard (Medium)
View Full Terrain H2O Breakdown
4.8(3,035 reviews)
Fit TendencyTrue to Size
Width ProfileStandard (Medium)
View Full THERMOBALL Traction Bootie 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-0.68 mm
Width Delta-0.15 mm

Interactive Size Converter

Select what size you wear in the Terrain H2O to see your calculated size in the THERMOBALL Traction Bootie.

Recommended Size in The North Face THERMOBALL Traction Bootie
US 692% Match

Internal shoe cavity difference: -0.7 mm (snugger)

Alternate option if between sizes: US 6.5 (73% match)

Complete Size Conversion Matrix

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

Terrain H2O (US)Internal CavityTHERMOBALL Traction Bootie EquivalentMatch AccuracyFit Difference
US 4.5234 mmUS 3.525%+6.3 mm
US 5238 mmUS 3.573%+2.3 mm
US 5.5241 mmUS 3.592%-0.7 mm
US 6244 mmUS 492%-0.7 mm
US 6.5248 mmUS 4.592%-0.7 mm
US 7251 mmUS 592%-0.7 mm
US 7.5254 mmUS 5.592%-0.7 mm
US 8258 mmUS 692%-0.7 mm
US 8.5261 mmUS 6.592%-0.7 mm
US 9268 mmUS 792%-0.7 mm
US 9.5271 mmUS 7.592%-0.7 mm
US 10274 mmUS 892%-0.7 mm
US 10.5278 mmUS 8.592%-0.7 mm
US 11281 mmUS 992%-0.7 mm

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Frequently Asked Questions

How does the Terrain H2O size compare to the THERMOBALL Traction Bootie?

Both shoes share a very similar length profile. We recommend ordering your standard size in both. The Terrain H2O has an internal fit offset of 0.84mm compared to 0.16mm for the THERMOBALL Traction Bootie.

Do these shoes fit wide feet comfortably?

The Terrain H2O has a roomy/wide width profile, while the THERMOBALL Traction Bootie is roomy/wide.