Calculate demand, protection current, and anode mass. Use inputs for pipelines, tanks, foundations, and piles. Build safer corrosion mitigation plans with clear design outputs.
| Item | Example Value |
|---|---|
| Total surface area | 250 m² |
| Coating breakdown factor | 3% |
| Design current density | 20 mA/m² |
| Design life | 20 years |
| Anode capacity | 780 Ah/kg |
| Anode efficiency | 90% |
| Utilization factor | 85% |
| Safety factor | 20% |
| Effective anode capacity | 596.70 Ah/kg |
| Required current | 0.1500 A |
| Required anode mass | 52.85 kg |
| Estimated 12 kg anodes | 5 |
Exposed bare area = Total surface area × Coating breakdown factor
Required current (A) = Exposed bare area × Current density (mA/m²) ÷ 1000
Base charge demand (Ah) = Required current × Design life × 8760
Design charge demand (Ah) = Base charge demand × (1 + Safety factor)
Effective anode capacity (Ah/kg) = Anode capacity × Efficiency × Utilization factor
Required anode mass (kg) = Design charge demand ÷ Effective anode capacity
Estimated anode count = Ceiling of required anode mass ÷ Unit anode mass
This calculator is intended for preliminary sizing. Final cathodic protection design should be checked against project conditions, standards, and detailed corrosion engineering review.
1. Choose whether you want to enter a direct steel surface area or estimate area from cylindrical geometry.
2. Enter the coating breakdown factor to represent the share of steel expected to need protective current.
3. Add the design current density that matches the environment, coating condition, and project requirements.
4. Enter design life, anode capacity, efficiency, utilization factor, and safety factor for your selected anode concept.
5. Enter unit anode mass if you want the calculator to estimate the number of sacrificial anodes.
6. Press calculate to show the result above the form, then export the results as CSV or PDF.
Cathodic protection is a core corrosion control method for buried and submerged steel. Construction teams use it to extend service life and reduce unexpected repair costs. A good design helps pipelines, piles, tanks, sheet piles, and reinforcing steel stay protected in aggressive environments. This calculator gives a practical starting point for estimating protection current and sacrificial anode mass.
In construction projects, steel often faces moisture, salts, oxygen, and coating damage. Those conditions create corrosion cells that slowly consume metal. Cathodic protection reduces that loss by shifting the electrochemical balance. When designers combine coatings with cathodic protection, the coating lowers exposed steel area and the protection system supplies current to the damaged spots. That combination improves durability and maintenance planning.
This cathodic protection calculator focuses on common planning variables. You enter total steel surface area, coating breakdown factor, design current density, design life, anode capacity, efficiency, utilization, safety factor, and optional unit anode mass. The calculator then estimates exposed bare area, required current, total charge demand, effective anode capacity, total anode mass, and estimated anode quantity. These outputs help contractors, estimators, and engineers compare options before detailed design review.
The tool is useful during budgeting, tender preparation, rehabilitation planning, and preliminary material selection. It also helps teams understand how coating damage changes current demand. A small increase in breakdown factor can raise required current and anode weight quickly. That insight supports better coating specifications, inspection planning, and lifecycle cost decisions. It also helps explain why corrosion mitigation should be addressed early, not after failures appear.
Use this calculator as a design aid, not as a replacement for project specific engineering. Soil resistivity, electrolyte chemistry, temperature, shielding, stray current, and code requirements can change the final system. Still, a fast estimate is valuable. It improves discussions between owners, contractors, and corrosion specialists. For many construction assets, early cathodic protection planning supports safer operation, longer service life, and more predictable asset performance. Because corrosion failures can disrupt production, traffic, utilities, and public safety, durable protection matters. Early estimates improve procurement timing for anodes, cables, rectifiers, and test stations. Better planning reduces change orders, avoids underdesigned systems, and supports clearer installation documentation and commissioning.
It estimates exposed steel area, required protection current, total ampere hours, effective anode capacity, total sacrificial anode mass, and optional anode quantity for preliminary planning.
It supports both at a planning level. The current output helps with impressed current sizing, while the anode mass output helps with sacrificial anode budgeting and comparison.
Cathodic protection current mainly serves damaged coating areas. As breakdown increases, exposed steel increases, current demand rises, and the required anode mass can grow quickly.
Use a project specific value from your corrosion engineer, standard, or test data. Current density depends on environment, coating condition, temperature, electrolyte, and protection criteria.
It is the usable fraction of anode material before replacement. Some mass remains unavailable because of shape, connections, resistance changes, and practical end of life limits.
Efficiency adjusts rated anode capacity to reflect real electrochemical performance. Lower efficiency means fewer ampere hours are delivered per kilogram, so more anode mass is required.
No. Use it for budgeting and early design only. Final systems should be checked for resistivity, spacing, interference, codes, monitoring locations, and detailed installation conditions.
Yes. It works for many buried or submerged steel assets when you can estimate total surface area and choose reasonable design inputs for the environment.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.