COSC Introduces 'Excellence Chronometer' Standard for Swiss Watches

New certification promises unparalleled precision and accuracy for luxury timepieces

Apr. 11, 2026 at 6:36am

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A close-up photograph of a highly polished, geometric stainless steel watch movement floating against a clean, monochromatic background, symbolizing the technical innovation and engineering prowess behind the Swiss watch industry's quest for chronometric excellence.The Swiss watch industry's relentless pursuit of mechanical precision is exemplified by COSC's new 'Excellence Chronometer' certification, pushing the boundaries of timekeeping accuracy.Houston Today

The Swiss watch industry is about to undergo a significant upgrade with the introduction of COSC's new 'Excellence Chronometer' standard. This more demanding certification will ensure Swiss-made mechanical watches meet even stricter accuracy requirements, pushing the boundaries of precision in the luxury watch market.

Why it matters

The new Excellence Chronometer standard is a response to a decade-long competition among top Swiss watch brands to develop the most accurate and technologically advanced timepieces. This move by COSC will further elevate the prestige and desirability of Swiss-made watches, catering to the growing demand for exceptional timekeeping performance.

The details

The Excellence Chronometer certification builds upon COSC's existing Certified Chronometer standard. In addition to the initial 15-day testing process, watches must now undergo an additional 5-day simulation of everyday wear using a specialized robot. To earn the Excellence Chronometer title, watches must meet tighter accuracy standards of -2 to +4 seconds per day, resist magnetic fields up to 200 Gauss, and maintain the promised power reserve.

  • COSC will initiate pilot testing for Excellence Chronometers in March 2026.
  • The new standard will be unveiled globally at Watches and Wonders in Geneva in April 2026.
  • Brands can begin submitting watches for Excellence Chronometer certification starting in October 2026.

The players

Contrôle Officiel Suisse des Chronomètres (COSC)

The official Swiss chronometer testing institute that has certified the accuracy of Swiss-made mechanical watches since 1973.

Rolex

A leading Swiss watch brand that has developed its own in-house Superlative Chronometer testing, guaranteeing accuracy within -2 to +2 seconds per day.

Omega

A Swiss watch brand that partnered with METAS in 2015 to create the Master Chronometer certification, which tests watches for accuracy, water resistance, and resistance to magnetic fields up to 15,000 Gauss.

Tudor

Rolex's sister brand that joined the METAS certification program in 2021, further raising the bar for Swiss watch accuracy.

Laboratoire de Précision

An independent chronometer-testing body established by Omega in 2024, using advanced instruments to continuously test watch movements over 15 days.

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What’s next

COSC will initiate pilot testing for Excellence Chronometers in March 2026, with the new standard being unveiled globally at Watches and Wonders in Geneva in April. Brands can then begin submitting their watches for Excellence Chronometer certification starting in October 2026.

The takeaway

The introduction of the Excellence Chronometer standard by COSC represents a significant milestone in the ongoing quest for precision and accuracy in the Swiss watch industry. This move will further elevate the prestige and desirability of Swiss-made mechanical watches, catering to the growing demand for exceptional timekeeping performance among luxury consumers.