Beam Calculator
Calculate the required beam size for structural loads
Load Parameters
Typical: 40 PSF residential, 50-100 PSF commercial
Important Notice
This calculator provides preliminary estimates only. Consult a licensed structural engineer for final design and approval.
Results
Recommended Beam Size
2×8
Douglas Fir-Larch
Total Load
640 lbs
53.3 lbs per linear foot
Bending Moment
960 ft-lbs
Section Modulus
13.14 in³
Required: 8.53 in³
Deflection
0.290 inches
L/496 ✓ Acceptable
Notes:
• Maximum deflection: L/360 for floors
• Assumes simple span, uniform load
• Grade #2 or better lumber
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Editorial Note
MyCalcBuddy Editorial Team
This page is maintained as an educational calculator reference.
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Formula Source: Standard Mathematical References
by Various
🔄Last reviewed: May 2026
✓Formula checks are based on standard references and internal QA review.