The Accuracy Reality
Digital calipers are rated for accuracy at a specific temperature (usually 20°C). Mitutoyo specifies ±0.02mm for most models. iGaging specifies ±0.03mm. In practice, at room temperature, the real-world difference between a $20 iGaging and a $200 Mitutoyo is approximately 0.01mm — invisible to most users, significant to machinists making parts that must fit to tolerance.
Where the Money Goes
Stainless steel quality: Mitutoyo uses proprietary hardened stainless that resists wear significantly better. iGaging uses standard 420 stainless that shows measurable wear after 500+ measurements on abrasive materials (aluminum, some composites).
Depth of field / rack quality: The measuring rack in Mitutoyo is polished to tolerances that ensure consistent accuracy across the entire measurement range. Budget calipers often show different accuracy at 50mm vs 150mm.
Repeatability: Mitutoyo reads the same dimension multiple times with the same result every time. Budget calipers can show 0.02-0.04mm variation between readings of the same dimension.
Battery life: Mitutoyo: 5+ years of regular use. iGaging: 6-12 months.
Our Picks
For machinists and professionals: Mitutoyo CD-6"ASX ($230). The +/-0.02mm accuracy is real and consistent. The resale value after 10 years is approximately 60% of original cost — quality tools hold value.
For makers and hobbyists: iGaging OriginPlus ($22). The $20 price point makes calibration less stressful (you're not worried about damaging an expensive tool). Accuracy is adequate for all non-critical measurements. Replace when it starts showing inconsistent readings.