Lap Length Calculator
Calculate rebar lap splice length based on ACI 318 requirements.
Splice Parameters
PSI
ksi
Class A: As provided / As required less than or equal to 2. Class B: All other cases.
in
in
Required Lap Length
28"
2.33 ft | 37 db
Bar Diameter
0.750"
Development Length
21.3"
Splice Multiplier
1.3x
Confinement Factor
2.00
Modification Factors:
Psi_t (Location)1.00
Psi_e (Coating)1.00
Psi_s (Size)0.80
Lambda (Concrete)1.00
ACI 318 Reference
Lap splice length calculated per ACI 318-19 Section 25.5. Class A splice: 1.0 ld when As provided / As required >= 2 and no more than 50% spliced. Class B splice: 1.3 ld for all other cases.
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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.