Data source and methodology

AuthoritativeDataSource: U.S. Department of Labor — Fair Labor Standards Act (FLSA) (federal overtime rules) and California DIR — Overtime (daily overtime & double time), plus Singapore MOM — Overtime. All links accessed for rule definitions and examples. Tutti i calcoli si basano rigorosamente sulle formule e sui dati forniti da questa fonte.

The formula explained

For a base hourly rate \( r \), hours worked \( h_d \) on day \( d \), and thresholds:

Daily split (if enabled): \[ \begin{aligned} \text{reg}_d &= \min(h_d, T_{1}) \\ \text{ot1}_d &= \min\big(\max(h_d - T_{1}, 0), \max(T_{2}-T_{1}, 0)\big) \\ \text{ot2}_d &= \max(h_d - T_{2}, 0) \end{aligned} \] Weekly adjustment (tier-1) with threshold \( W \): \[ \text{extraOT1} = \max\big(H_{\text{total}} - W - \sum_d \text{ot1}_d - \sum_d \text{ot2}_d,\, 0\big) \] Regular hours are reduced by \(\text{extraOT1}\).

Pay: \[ \begin{aligned} P_{\text{reg}} &= r \cdot H_{\text{reg}} \\ P_{\text{ot1}} &= (m_1 \cdot r) \cdot H_{\text{ot1}} \\ P_{\text{ot2}} &= (m_2 \cdot r) \cdot H_{\text{ot2}} \\ P_{\text{total}} &= P_{\text{reg}} + P_{\text{ot1}} + P_{\text{ot2}} \end{aligned} \]

Glossary of variables

  • r: Base hourly rate.
  • W: Weekly overtime threshold (hours/week).
  • T1, T2: Daily thresholds for OT tier 1 and tier 2.
  • m1, m2: Multipliers for OT tier 1 and tier 2.
  • Hreg, Hot1, Hot2: Regular, OT tier 1, and OT tier 2 hours for the week.

How it works: a step-by-step example

Preset: California. Rate: \$25/h. Hours: 9, 10, 8, 12, 6, 0, 0 (Mon–Sun).

  1. Daily split:
    • Mon 9h → 8h reg, 1h OT1
    • Tue 10h → 8h reg, 2h OT1
    • Wed 8h → 8h reg
    • Thu 12h → 8h reg, 4h OT1
    • Fri 6h → 6h reg
  2. Totals before weekly rule: reg 38h, OT1 7h, OT2 0h; total hours 45h.
  3. Weekly rule (40h): extraOT1 = max(45 − 40 − 7 − 0, 0) = 5 − 7 = 0 → no extra weekly OT.
  4. Pay: reg \$25×38 = \$950; OT1 1.5×\$25×7 = \$262.50; total = \$1,212.50.

FAQ

Does FLSA require daily overtime?

No. The federal FLSA uses a weekly threshold (typically 40 hours). Some states (e.g., California) add daily rules.

Can I change multipliers (e.g., 1.75×)?

Yes. Use the Custom preset and set the tier multipliers as needed.

How are weekly and daily rules combined?

Daily OT is computed first; then any remaining hours above the weekly threshold are treated as additional Tier-1 overtime (no double counting).

Are allowances or bonuses included in the overtime base?

Often they are excluded, but this depends on contract and local law. When in doubt, consult HR or a labor professional.

Does Singapore have a monthly cap on OT?

Yes, Singapore MOM policies include caps (e.g., 72 OT hours/month) and specific eligibility rules. This calculator focuses on weekly arithmetic; always check current MOM guidance.

Is this calculator legal advice?

No. It is an educational tool; verify with the applicable labor authority or a qualified advisor for your situation.

Tool developed by Ugo Candido. Content verified by the CalcDomain Editorial Board.
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