--- title: "CalRegister — Instrument Calibration Due Date Calculator" description: "Calculate the next calibration due date from the last calibration and an interval in months. Month-end dates clamp correctly. Free planning tool, not a calibration record." canonical_url: "https://calregister.io/tools/calibration-due-date-calculator" meta: "og:description": "Calculate the next calibration due date from the last calibration and an interval in months. Month-end dates clamp correctly. Free planning tool, not a calibration record." "og:title": "CalRegister — Instrument Calibration Due Date Calculator" --- > Index of every page on this site: [llms.txt](https://calregister.io/llms.txt) [CalRegister](https://calregister.io/) / Tools # **Instrument calibration due date calculator ** Enter the last calibration date and the interval in months. The next due date is calculated in UTC date-only maths, so month-end dates clamp instead of rolling into the next month. ## **Result ** **Current** Next calibration due **2027-11-10** ISO date, YYYY-MM-DD
Days remaining
**365 days**
Interval
**12 months**
**Want the reminder sent for you? ** CalRegister emails the lead times you choose and repeats while an instrument is overdue. [**Start free trial **](https://calregister.io/signup) This calculator is a planning aid, not a calibration record. It stores nothing and submits nothing. The date on the certificate and the procedure in your quality system remain authoritative. ## **How the due date is calculated ** 01 ### **Add the interval ** Next due is the last calibration date plus the interval in whole months. 02 ### **Clamp the month end ** 31 Jan plus one month is 28 Feb, or 29 Feb in a leap year. 31 Mar plus one month is 30 Apr. The date never rolls into the next month. 03 ### **Compare with today ** The calculator counts whole UTC days. Due today is not overdue. Anything before today is. ```json {"@context":"https://schema.org","@graph":[{"@id":"https://calregister.io/#website","@type":"WebSite","url":"https://calregister.io/"},{"@id":"https://calregister.io/tools/calibration-due-date-calculator#webpage","@type":"WebPage","description":"Calculate the next calibration due date from the last calibration and an interval in months. Month-end dates clamp correctly. Free planning tool, not a calibration record.","name":"Instrument Calibration Due Date Calculator","url":"https://calregister.io/tools/calibration-due-date-calculator","isPartOf":{"@id":"https://calregister.io/#website"},"potentialAction":[{"@type":"ReadAction","target":["https://calregister.io/tools/calibration-due-date-calculator"]}]}]} ``` ## Sitemap See the full [sitemap](https://calregister.io/sitemap.md) for all pages.