“More or less” is not a strategy when the bill arrives. The better moment to look at the numbers is now, while changing your mind is still cheap.
The text below the tool isn't decoration. Your inputs stay on your device — there is no server side to this tool at all.
What it's for
Between them sits an exact expression. The values entered here are Active power (W), Line-to-line voltage (V), Power factor (cos φ), Efficiency (%).
For Singapore, use the units printed beside each field and do not assume that a familiar name means the same measurement system. Three-phase current calculation tool turns cable and wire sizes into the right choice — mm² or AWG, current rating, voltage drop, conduit diameter. Solid — for permanent installs in walls and conduit. Undersized wire overheats insulation; oversized wire is wasted money.
The calculation in plain English
Over a 30 m three-phase run the voltage drop is around 1.5% — well inside the 3% standard limit. Example: 7500 A load on XLPE cable in conduit at 25°C requires a specific mm² cross-section. For 32 A that's 6 mm² (4 mm² would be marginal).
Use when designing residential or industrial wiring, powering a motor over a long run (voltage drop), on a solar system (panel–inverter link), for audio or network cable over long distance, or converting between European and US specs. Never save on cable — the cost is tiny compared to the risk. Keep the original measurement, invoice, specification or log beside the calculation so that a misplaced decimal point can be found.
Operating the calculator
For runs longer than 50 m verify voltage drop (max 3% lighting, 5% motors). Second: ignoring voltage drop on long runs — a motor at 100 m won't commence on undersized wire.
Solar systems: UV-resistant cable on the DC side. Always pick with 20–25% margin over computed current.
Classic: sizing by nominal current without derating for temperature and install method (at 40°C and bunched cables ampacity drops 30–40%). Third: confusing AWG with mm² (12 AWG ≠ 12 mm², it's 3.31 mm²).
Overhead runs: add mechanical protection.
When this number matters
- Local notes: Numbers use SGD, metric units and IRAS defaults where applicable.
- VAT / sales tax: Singapore's GST is 9% (as of 1 Jan 2024). Financial services and residential rentals are exempt; exports zero-rated.
- Electrical supply: 230 V / 50 Hz, Type G plug (same as UK).
- Currency & format: Singapore dollar (SGD, S$).
- Units of measure: Fully metric.
Who gets the most out of this
Stranded is more flexible but slightly costlier. Stranded — for movable connections, machinery, extension cords, automotive.
Where income, tax or contributions are involved, the reference framework is IRAS and CPF (Central Provident Fund) — personal income tax 0–24%, GST 9%. Typical visitors are users across Singapore's CBD, Jurong and Tampines comparing offers or checking a bill, so the worked examples below use sensible local values rather than abstract numbers.
Worth knowing before you rely on the result
Every figure above applies to Singapore specifically and is reviewed when the rules change. AWG to mm² uses S = 0.012668 × 92^((36-AWG)/19.5) × 1000. Calculations follow IEC 60364 (Europe) and NEC 310 (US): ampacity per standard table derived from insulation type (PVC, XLPE) and install method (conduit, free air, buried). Singapore's rules are unusually flat and predictable, and Three-phase current calculator reflects that structure directly.
Where results get distorted
Equally exact, but mm² is a direct physical dimension (area) and AWG is a log scale (smaller number = thicker wire). This Three-phase current calculator is tuned to practice in Singapore: amounts are shown in Singapore dollar (SGD, S$), formatted as S$1,234.56, and quantities use fully metric. Numbers use SGD, metric units and IRAS defaults where applicable.
Recalculate after changing one input at a time; this gives which assumption controls the computed figure and makes an unexpected answer easier to diagnose.
In short
Keep the formula in mind even when you use the tool. That is the whole trick: compute first, decide second.
Singapore-specific questions
Is this Three-phase current calculator valid for Singapore?
Yes. It uses Singapore dollar (SGD, S$) and fully metric, and any tax or contribution reference follows IRAS rules.
Which units and number format are used?
Amounts display as S$1,234.56 and quantities in fully metric — the official convention in Singapore.
Which pension and tax model is assumed?
CPF LIFE payouts from 65. The tax framework is personal income tax 0–24%, GST 9%.