plus12: How it all started

In 2001, we were commissioned by the Austrian Federal Ministry of Health to answer this question: Do Austrian children’s shoes fit?

To find out if a shoe fits, we measure the amount of extra space it offers (for a proper fit, shoes need to be at least 12 mm longer than the length of the feet). This means we needed to measure both children’s feet and their shoes. Measuring feet is easy enough, but in 2001 there was no instrument available for reliably measuring the inside length of shoes. So we developed the plus12, a tool to measure both shoes and feet. And we called it plus12 because when measuring the foot, it automatically adds 12 mm to the length and you know right away how long a properly fitting shoe needs to be.

Originally, the plus12 was developed just to be a helpful tool for our research, but then parents discovered how useful it is.

Plus12 foot and shoe measuring device within shoe

Measuring the inside length of a shoe

Plus12 foot and shoe measuring device with foot

Taking the foot measurement (incl. 12 mm extra space)

How the plus12 works

A 2-minute video about little feet and their shoes

The Children’s Feet – Children’s Shoes research team

Children’s Feet – Children’s Shoes is an independent team of researchers.

Research projects

2001-2003: Research project “Children’s Feet – Children’s Shoes,” commissioned by the Federal Ministry
2005-2007: Research project “Kids: Healthy feet – healthy life,” commissioned by the Austrian Federal Ministry of Health and the Fonds Gesundes Österreich (Fund for a Healthy Austria)


2004: plus12: Tool for measuring children’s feet and shoes

2007: plus12base: A practical accessory for the plus12, a large red plastic foot the plus12 snaps into securely; perfect for retailers

2013: plus12med: Tool for measuring feet and shoes for diabetic patients

2011: plus12fit: A practical cardboard strip for serial measurements; for feet and the inside length of shoes

2019: plus12socks: Innovative socks, perfectly straight along the big toe, developed and made in Austria


plus12socks Socken Zeichnung mit Füßen von Erwachsenen und Kindern


2000: KINZ, Wieland: „Kinderfüße-Kinderschuhe. Alles Wissenswerte rund um kleine Füße und Schuhe“. ISBN 3-00-005879-6

2004: KINZ, Wieland: „Kinderfüße-Kinderschuhe. Angewandte Forschung als Grundlage der Gesundheitsaufklärung“. Dissertation, University of Salzburg/ Medical University of Vienna

2009: Klein, Christian; Groll-Knapp, Elisabeth; Kundi, Michael; Kinz, Wieland: “Increased hallux angle in children and its association with insufficient length of footwear: A community based cross-sectional study” BMC Musculoskeletal Disorders, December 17, 2009.

2014: Klein T, Kinz W, Zembsch A, Groll-Knapp E, Kundi M.: “The hallux valgus angle of the margo medialis pedis as an alternative to the measurement of the metatarsophalangeal hallux valgus angle” BMC Musculoskelet Disord. 2014;15:133‏

2015: Kinz, W., Groll-Knapp, E. & Klein, C: “Kinder in zu kurzen Schuhen”. (Children wearing shoes of insufficient length) Pädiatrie & Podologie 3, 2015.

2020: Kinz W, Groll-Knapp E, Kundi M: Hallux valgus in pre-school-aged children: the effects of too-short shoes on the hallux angle and the effects of going barefoot on podiatric health“. Footwear Science, Volume 13, 2021 issue 1