Beam Deflection Calculator Simply Supported with Partial Load

This calculator covers a simply supported beam with a uniformly distributed load applied over only part of its span, rather than the full length — for example, a beam partially covered by a load such as stacked material, a partial floor load, or plant equipment that only occupies part of the beam's length. Because the load doesn't cover the whole span, the support reactions aren't simply half the total load each — they depend on where the loaded section sits relative to each support.

For a UDL covering the entire span, see our simpler Simply Supported, Uniform Load calculator instead.

This calculator calculates the End Slopes, Support Reactions, Maximum Deflection and Maximum Stress in a simply supported beam with partial loads.

Enter your values as required and press SOLVE, your results will be displayed. If you change any unit types or values please press SOLVE again.

CLEAR ALL clears all fields.

SIMPLY SUPPORTED BEAM - PARTIAL UNIFORM LOAD

MATERIAL: Aluminium 2024-T4Aluminium 6061-T6Aluminium 7075-T3BrassCast IronCopperLeadMagnesiumPhosphur BronzeStainless Steel, 304Stainless Steel, 316Steel, S235Steel, S275Steel, S355Steel, 4130Steel, ASTM A36Steel, ASTM A441Titanium, Grade 2Titanium, Grade 5

MOMENT OF INERTIA:

mm4cm4m4Inch4

TOTAL LENGTH: (L)

MetresCentimetresMillimetresInches

LOAD LENGTH: (A)

MetresCentimetresMillimetresInches

DISTANCE TO NEUTRAL PLANE: (Z)

MetresCentimetresMillimetresInches

MAXIMUM LOAD INTENSITY : (w)

N/mmkN/mlb/inlb/ft

END SLOPE A: (A°)

DegreesRadians

END SLOPE: (B°)

DegreesRadians

SUPPORT REACTION: (WA)

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SUPPORT REACTION: (WB)

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MAXIMUM DEFLECTION: (y)

MetresCentimetresMillimetresInches

MAXIMUM DEFLECTION LENGTH :(B)

MetresCentimetresMillimetresInches

MAXIMUM STRESS:

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RELATED PAGES

• Simply Supported, Uniform Load (full span)
• Simply Supported, Varying Load

FREQUENTLY ASKED QUESTIONS

Where does maximum deflection occur for a partial UDL?

Not necessarily at mid-span — the location shifts toward the loaded section, particularly if the load is positioned off-centre. This calculator locates the true maximum deflection point rather than assuming it's at the beam's centre.

How do I model two separate partial loads on the same beam?

This calculator handles a single partial UDL. For multiple separate loaded sections, you'd typically need to calculate each load's contribution separately and superimpose (add together) the results at each point along the beam.