ISO/IEC 17025 Measurement Uncertainty Calculator (Excel)

Stop struggling with complex statistics. Generate audit-ready Uncertainty Budgets in minutes.

Calculating Measurement Uncertainty is the #1 technical challenge for calibration and testing laboratories. One calculation error or a missing source of uncertainty can lead to a non-conformance during your ISO/IEC 17025 assessment.

This Universal Uncertainty Calculator automates the entire GUM (Guide to the Expression of Uncertainty in Measurement) process. It handles the statistical distributions, divisors, and sensitivity coefficients for you—so you can focus on your measurements.

✅ Universal Design: Works for Dimensional, Pressure, Electrical, Temperature, Mass, and Torque disciplines. 

✅ Audit Ready: Fully aligned with ISO/IEC 17025:2017 and JCGM 100:2008 (GUM).

Key Features:

• Automated Type A Evaluation: Simply input your 10 repeatability readings, and the tool calculates Mean, Standard Deviation, and Standard Uncertainty automatically.
• Smart Type B Table: Features a built-in logic engine. Select your distribution (Normal, Rectangular, U-Shaped) from a dropdown, and the tool automatically applies the correct divisor etc.).
• Built-In Knowledge Bank: Includes a reference library of common uncertainty sources (Hysteresis, Drift, Resolution, Thermal Expansion) categorized by discipline, helping you ensure you haven't missed anything.
• Visual Dashboard: Automatically generates a Contribution Bar Chart (to see which error source is dominant) and a Probability Bell Curve (visualizing the 95% confidence interval) for your reports.
• Results Summary: Instantly provides your Combined Uncertainty (uc​) and Expanded Uncertainty (U) with a coverage factor of k=2.

What You Get:

• 1 x Excel Calculation Tool (.xlsx): The complete, unlocked calculator.
• 1 x User Instruction Manual (PDF): A step-by-step guide on how to populate the tool and interpret the data.

System Requirements:

• Microsoft Excel 2010 or newer.
• No Macros/VBA used (Safe for strict IT security environments).

License: This purchase grants a lifetime license for use within a single company or laboratory.

3d-Service Metrology LTD Real tools for working laboratories.