{"h1":"At what age is the WHO-GMM used for a child?","faq":[{"a":"The WHO-GMM is used for infants and young children, roughly from 4 months to about 24 months. It maps the windows for six gross-motor milestones from early sitting through to walking alone.","q":"What age range does the WHO-GMM cover?"},{"a":"It covers six gross-motor milestones: sitting without support, hands-and-knees crawling, standing with assistance, walking with assistance, standing alone, and walking alone — each with an expected age window.","q":"What milestones does the WHO-GMM measure?"},{"a":"Each milestone has a window, not a single deadline, so some variation is normal. If your child clearly passes the later edge of a window without reaching a milestone, a gentle developmental review is wise.","q":"Should I worry if my baby reaches a milestone late?"}],"lang":"en","slug":"at-what-age-is-the-who-gmm-developmental-assessment-used-for-a-child","title":"At What Age Is the WHO-GMM Used for a Child?","entity":{"key":"who_gmm","kind":"instrument","name":"WHO Windows of Achievement for Gross Motor Milestones","slug":"who-gmm"},"lenses":[{"kind":"stakeholder","label":"Parent","value":"parent"},{"kind":"intent","label":"Definition","value":"definition"},{"kind":"lifecycle","label":"Measure","value":"measure"},{"kind":"route","label":"Screen","value":"screen"},{"kind":"empowerment","label":"Early Clarity","value":"early_clarity"}],"parent":{"key":"assessments","label":"Assessments"},"related":[{"lang":"en","slug":"at-what-age-is-the-gmfm-developmental-assessment-used-for-a-child","title":"At what age is the GMFM developmental assessment used for a child?"},{"lang":"en","slug":"how-does-the-who-gmm-compare-with-the-abilityscore-developmental-assessment","title":"How does the WHO-GMM compare with the AbilityScore developmental assessment?"},{"lang":"en","slug":"what-are-the-key-motor-milestones-in-early-childhood","title":"Key motor milestones in early childhood"},{"lang":"en","slug":"should-my-child-have-a-who-gmm-assessment-and-what-does-it-involve","title":"Should My Child Have a WHO-GMM Assessment?"},{"lang":"en","slug":"when-is-the-who-gmm-indicated-and-what-are-its-strengths-and-limits-in-early-childhood","title":"When is the WHO-GMM indicated, and what are its strengths and limits?"},{"lang":"en","slug":"what-is-the-who-windows-of-achievement-for-gross-motor-milestones-who-gmm-and-what-does-it-assess","title":"What is the WHO Windows of Achievement for Gross Motor Milestones (WHO-GMM)?"}],"summary":"The WHO Windows of Achievement for Gross Motor Milestones (WHO-GMM) is used for infants and young children, roughly from 4 months to about 24 months of age. It maps the typical age window in which most healthy children reach six key gross-motor milestones — sitting, crawling, standing and walking. Each milestone has a window rather than a single deadline, allowing for normal variation, and it serves as a reference to notice when a milestone falls outside its expected range.","answer_md":"*A handy ruler for the early walking years — the WHO-GMM tells us the typical age range in which a child reaches each big motor milestone.*\n\n## In short\nThe **WHO Windows of Achievement for Gross Motor Milestones (WHO-GMM)** is used for **infants and young children, roughly from 4 months to about 24 months (2 years)** of age. It maps the typical age *window* in which most healthy children reach six key gross-motor milestones — sitting, standing, crawling and the early steps of walking. It is a reassuring reference for the early movement years, not a test that continues into the school years.\n\n## What the WHO-GMM covers and when\nThe WHO-GMM describes six gross-motor milestones, each with a *window* — an early-to-late age range rather than a single deadline — that reflects how much healthy variation is normal between babies. In broad terms these windows span:\n\n- **Sitting without support** — from around 4 months\n- **Hands-and-knees crawling** — from around 5–6 months\n- **Standing with assistance** — from around 5–6 months\n- **Walking with assistance** — from around 6 months\n- **Standing alone** — from around 7 months\n- **Walking alone** — typically by around 18 months, with the window extending towards 18–24 months\n\nBecause each milestone has a window, a baby who sits or walks a little earlier or later than a friend is usually still developing perfectly well. The WHO-GMM simply helps families and clinicians notice when a milestone falls outside its expected window, which is a gentle prompt for a closer look — never an automatic concern on its own.\n\n## When a review helps\nConsider a developmental review if your child has clearly passed the later edge of a window without reaching that milestone — for example, not sitting independently well beyond the sitting window, or not walking by around 18 months — or if you notice stiffness, floppiness, or one side of the body being used much less than the other. Early observation protects a child's movement, confidence and play.\n\n## The Pinnacle way\nThis is general information, not a diagnosis — a clinical [AbilityScore®](/ask/what-is-the-abilityscore-and-how-is-it-calculated) and any diagnosis are formed only at a Pinnacle Blooms Network centre, under qualified clinician care, never from an app or form. Our team uses references like the [WHO-GMM](/who-gmm) alongside a full developmental picture, then shapes any helpful support, which may include [occupational therapy](https://www.pinnacleblooms.org/best-occupational-therapy-center-india-proven-improvement-rate) for movement and play skills.\n\n## Trusted sources\nWHO Multicentre Growth Reference Study, which established the Windows of Achievement for the six gross-motor milestones; WHO Nurturing Care Framework on early childhood development; CDC and AAP/HealthyChildren guidance on motor milestones.\n\n**Next step —** If your child is in the early walking years and you'd like reassurance about their movement milestones, book a developmental review to map their progress against the expected windows.","canonical":"https://pinnacleblooms.org/ask/at-what-age-is-the-who-gmm-developmental-assessment-used-for-a-child","editorial":{"reviewed_at":"2026-06-11T20:12:18.613642+00:00","reviewed_by":null,"developed_by":"SETU Consortium · Pinnacle Blooms Network"},"alternates":[{"href":"https://pinnacleblooms.org/ask/at-what-age-is-the-who-gmm-developmental-assessment-used-for-a-child","lang":"en","indexable":true}],"dimensions":[{"key":"assessments","label":"Assessments"}],"meta_title":"WHO-GMM: At What Age Is It Used?","meta_robots":"index, follow, max-image-preview:large","everyday_tip":"Give your baby plenty of supervised floor and tummy time — reaching for toys just out of grasp encourages rolling, sitting and crawling naturally, without any pressure or special equipment.","published_at":"2026-06-10T14:12:00.219358+00:00","reading_paths":[{"key":"understand","items":[{"lang":"en","slug":"what-is-the-who-windows-of-achievement-for-gross-motor-milestones-who-gmm-and-what-does-it-assess","title":"What is the WHO Windows of Achievement for Gross Motor Milestones (WHO-GMM)?","reason":"Linked from this answer"},{"lang":"en","slug":"at-what-age-is-the-gmfm-developmental-assessment-used-for-a-child","title":"At what age is the GMFM developmental assessment used for a child?","reason":"Linked from this answer"}],"label":"Understand the subject","total":2},{"key":"signs","items":[{"lang":"en","slug":"what-are-the-key-motor-milestones-in-early-childhood","title":"Key motor milestones in early childhood","reason":"Linked from this answer"}],"label":"Recognise signs & concerns","total":1},{"key":"assess","items":[{"lang":"en","slug":"should-my-child-have-a-who-gmm-assessment-and-what-does-it-involve","title":"Should My Child Have a WHO-GMM Assessment?","reason":"Linked from this answer"},{"lang":"en","slug":"when-is-the-who-gmm-indicated-and-what-are-its-strengths-and-limits-in-early-childhood","title":"When is the WHO-GMM indicated, and what are its strengths and limits?","reason":"Linked from this answer"},{"lang":"en","slug":"how-does-the-who-gmm-compare-with-the-abilityscore-developmental-assessment","title":"How does the WHO-GMM compare with the AbilityScore developmental assessment?","reason":"Linked from this answer"}],"label":"Understand assessment","total":3}],"what_to_watch":"Not sitting independently well beyond the sitting window, not walking by around 18 months, or signs of stiffness, floppiness, or one side of the body being used much less than the other.","authority_links":[{"url":"https://www.who.int/tools/child-growth-standards","label":"WHO Child Growth Standards & Motor Milestones"},{"url":"https://www.cdc.gov/child-development","label":"CDC Developmental Milestones"},{"url":"https://www.healthychildren.org","label":"AAP HealthyChildren on infant milestones"}],"last_reviewed_at":"2026-06-10T14:12:00.219358+00:00","meta_description":"The WHO-GMM (Windows of Achievement for Gross Motor Milestones) is used for infants from about 4 to 24 months, mapping sitting, crawling, standing and walk","related_materials":[],"related_techniques":[]}