Build reliable panel schedules for every project. Enter circuits, loads, and demand factors very easily. Export tables, totals, and phase currents in seconds instantly.
| Circuit | Description | Type | Qty | Per Unit | Demand % | Poles | Breaker | Wire | Notes |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Lighting - Open Office | W | 1 | 1200 | 80 | 1 | 20A | 2.5 mm² | LED panels |
| 2 | Receptacles - Workstations | VA | 1 | 1800 | 100 | 1 | 20A | 2.5 mm² | General outlets |
| 3 | Split AC - Meeting Room | W | 1 | 1500 | 100 | 2 | 20A | 4 mm² | L-L |
| 4 | Server Rack UPS | W | 1 | 900 | 100 | 1 | 20A | 2.5 mm² | Critical load |
Accurate schedules begin with consistent circuit naming and load units. Use clear descriptions, keep quantities realistic, and separate lighting, receptacles, HVAC, and dedicated equipment. For watt-based entries, the tool converts to apparent power using the selected power factor. This keeps demand totals comparable across mixed load types and supports reliable current estimates for takeoffs and better coordination.
Demand percentage lets you model expected utilization rather than installed capacity. Apply lower values to general receptacles and higher values to critical or continuous equipment. The calculator multiplies each circuit connected VA by demand percent to produce demand VA, then aggregates totals. A spare allowance can be added to protect future expansion and reduce retrofit risk. Document assumptions so reviewers understand intent and constraints clearly.
For three-phase systems, distributing single-pole loads across phases improves voltage stability and reduces neutral stress. The schedule assigns single-pole circuits sequentially to A, B, and C to approximate balance. Two-pole loads are treated as line-to-line, while three-pole loads share demand across all phases. The imbalance metric highlights uneven phase currents for further refinement.
Main current is computed from demand plus spare using standard apparent-power relationships. Single-phase uses VA divided by line-to-neutral voltage, while three-phase uses VA divided by √3 times line-to-line voltage. The tool then applies a 125% design allowance and rounds up to a common main device size. A reference copper conductor size is suggested for early estimating.
Panel schedules support procurement, installation, and inspection when they are complete and traceable. Populate breaker and wire fields to align with drawings and material takeoffs. After calculation, export CSV for spreadsheets or PDF for submittals and site packages. Use notes to capture special conditions such as dedicated circuits, critical loads, or coordination with mechanical equipment and controls.
1) How should I enter motor or HVAC loads?
Enter nameplate watts or VA, choose poles, and apply an appropriate demand percent. For motors, confirm starting current, protection method, and code requirements separately during final design.
2) What does power factor change in the calculation?
If you enter watts, the calculator converts to VA using VA = W ÷ PF. VA-based entries are not changed by power factor and remain as provided.
3) Can I use this for single-phase panels?
Yes. Select 1P2W and provide line-to-neutral voltage. The calculator treats all circuits as one phase and computes current using I = VA ÷ VLN.
4) How is phase assignment handled?
Single-pole circuits rotate across A, B, and C in order. Two-pole circuits occupy two phases, and three-pole circuits share across all phases. Adjust ordering if you need a different balancing strategy.
5) Are breaker and wire sizes final?
No. Recommendations are estimating-level. Verify temperature rating, installation method, voltage drop, derating, and local rules before issuing construction documents.
6) Why include a spare allowance?
Spare capacity supports future additions without replacing the main device. It also reduces retrofit downtime by reserving demand capacity for anticipated expansion.
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.