Anchor Bolt Embedment

Required embedment depth from public bond strength formula.

Run the calculator

Example

You enter

Uplift load (lb) 5000
Bolt diameter (in) 0.625
Concrete fc (psi) 3000

You get

Required embedment 66.42 in
Required embedment (ft) 5.535
T (lb) 5000

Details, formula, and sources

Bond-strength embedment ld = T / (0.7 x sqrt(f'c) x pi x d), with the cracked-concrete case taken as ld / 0.7 and the ACI 318 §17 critical edge distance flagged at 1.5 x hef. A screen, not the §17 concrete-breakout (Ncb) calculation.

ACI 318-19 §17 (Anchoring to Concrete). IBC 2021 (International Building Code). §1908 references ACI 318.

ACI 318 licensed; principles free in published structural texts.

Estimate. AHJ and licensed structural engineer govern.

Field names used by the API: uplift_lb, bolt_diameter_in, fc_psi, embedment_in, embedment_ft, T_lb

Manufacturer ICC-ES report user-supplied for post-installed anchors; required for code complianceICC-ES evaluation reports