Hole Size Calculator

Calculate the actual hole size range based on nominal size and tolerance values. This tool is essential for precision engineering, CNC machining, and tolerance analysis.

Hole Size
Calculator

mm
+mm
-mm
Hole Range: 0 - 0 mm
Formula: Min = Nominal + Lower, Max = Nominal + Upper
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Quick Answer

👉 Basic formula:

  • Minimum Size = Nominal Size + Lower Tolerance
  • Maximum Size = Nominal Size + Upper Tolerance

✔ Example:
Nominal = 10 mm
Tolerance = +0.021 / 0
→ Range = 10.000 – 10.021 mm

Formula (Hole Size Calculation)

Standard Formula:

Min = Nominal + Lower
Max = Nominal + Upper

Hole Size Example Table

Nominal (mm) Lower Tol (mm) Upper Tol (mm) Range (mm)
10 0 +0.021 10.000 – 10.021
20 -0.010 +0.010 19.990 – 20.010
50 -0.020 +0.030 49.980 – 50.030

How to Use This Calculator

  1. Enter nominal hole size (mm)
  2. Input upper tolerance (mm)
  3. Input lower tolerance (mm)
  4. Instantly get the hole size range (min – max)

✔ Real-time calculation
✔ Essential for tolerance analysis

Common Engineering Uses

1. Tolerance Stack-Up Analysis

  • Ensure proper fit between mating parts

2. CNC Machining Quality Control

  • Verify hole dimensions meet specifications

3. Fit Selection (Clearance / Interference)

  • Determine shaft-hole compatibility

4. Engineering Drawings

  • Define allowable dimensional variation

Important Notes

  • Upper tolerance is typically positive (+)
  • Lower tolerance can be:
    • Zero (unilateral tolerance)
    • Negative (bilateral tolerance)

👉 Always follow ISO or ANSI standards for tolerance specification.

Related Calculators

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  • Tolerance Calculator
  • Press Fit Calculator
  • Surface Roughness Calculator
  • Mm to Inches Calculator

FAQ

What is nominal size?

The target or basic dimension specified in a design.

What is tolerance?

The allowable variation from the nominal size.

What is unilateral tolerance?

Tolerance in one direction only (e.g., +0.02 / 0).

What is bilateral tolerance?

Tolerance in both directions (e.g., ±0.01).

Why is hole size range important?

It ensures proper fit, function, and assembly performance.

CNC Machining Shops

CNC Machining Shops

Need Precision CNC Machined Parts with Tight Tolerances?

Accurate tolerance control ensures performance and reliability.

👉 We offer:

  • High-precision CNC machining (±0.01 mm or tighter)
  • Advanced inspection and quality control
  • Support for ISO fits and tolerance standards
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Upload your drawing today and get a precision manufacturing solution.