Home›Pay, cost & hours

Shift schedule optimizer

Enter when the business operates and how people work. The calculator shows how many people you need, whether every hour is covered, each person’s hours and the payroll cost.

Educational simulation. Not investment advice. Results are estimates based on the data you enter and do not replace advice from a qualified professional.

Reviewed on Nov 1, 2026

Indicative calculator. It gives an estimate to compare schedules and costs; it does not exactly reproduce each country’s laws, collective agreements or your company’s rules. Applicable labor laws and agreements must be evaluated and taken into account; this is the user’s responsibility. The calculator does not check legal limits.

1When the company operates

Tick the days the company operates, the opening and closing times and how many people must be working at the same time (positions).

DayOpensClosesPositions

A closing time earlier than the opening time runs past midnight (e.g. 18:00 to 02:00). Opening equal to closing = 24 hours (e.g. 00:00 to 00:00).

2How people work

Unticked: each shift has its own team, sized to its positions. Ticked: teams rotate between shifts and all are sized to the largest shift.

Schedules in the study and hours worked per day (h:mm)

Tick the schedules for the comparison and calendars. Each shows the suggested default; change the hours if you like (accepts 7:20, 7h20, 7.5 or 720).

3Rules and cost
Settings: they come with typical values. Change only what is different in your company.

Overtime: premium by day of week (%)
Reference values by country (for information only; the fields are not changed):
  • United States (federal, FLSA): 40 h a week, overtime at 1.5× the regular rate; no federal premium for Sundays, holidays or night work. California: daily overtime above 8 h a day at 1.5× and above 12 h at 2×, plus the 7th consecutive day.
  • India: overtime at twice the ordinary rate beyond 9 h a day or 48 h a week; quarterly overtime caps vary by state.
  • Australia: depends on the modern award; typically 150% for the first hours and 200% after, Sunday 200% and public holidays 250%.
  • United Kingdom: no statutory overtime premium; 48 h average weekly limit, with individual opt-out.
  • Canada: set by each province (Ontario: 44 h a week, then +50%).
Daily overtime rules (such as California’s) are not modeled: the calculator counts overtime per week and uses the % of each weekday.

Night shift differential is set by company policy or agreement (no federal requirement); 0% leaves it out of the cost.

4Freelancers

Your inputs stay only on this browser and are not sent anywhere. Untick to delete them.

—People and cost of the reference schedule
—

People per team: rounding and optimization

People cannot be split: the calculated number is always rounded up. The optimization shows an option with fewer people.

Weekly coverage map

Each square is one hour. It shows whether operating hours have enough people.

Operating and coveredPeople missing (number = uncovered positions)Shift outside operating hoursClosed

Schedule comparison

Schedules ticked in step 2, with the same operating hours and rules. Tap a row to use that schedule.

Schedule calendars (4 weeks)

One table per ticked schedule, starting with the reference. Each row is a group of people with the same days off. Drag the table sideways to see all 28 days.

.xlsx spreadsheet with one sheet per ticked schedule (day-off groups, reserve, overtime, freelancers and people present over the 28 days), a Summary sheet (people, hours, overtime and cost) and a sheet with the shift times.

Next step

Take this page’s results to another calculator with the fields already filled in.

Overtime and night premium on the payslip →

The summary lists your inputs, results, formulas, assumptions and sources. The full report also includes the charts and interpretations, in color. In the print dialog, choose Save as PDF.

Method, assumptions and sources

Formulas

Hours worked per day = shift length − unpaid breaks; shifts built by the calculator = operating hours ÷ (hours worked + break), rounded up
Fixed team per shift: fewest people, using the schedule’s day-off groups, that keeps present ≥ positions on every day of the 4 weeks
Vacation and absence factor = work days per year ÷ (work days per year − vacation × days per week ÷ 7 − absences); calculated people = position-days per week ÷ days worked per person × factor
Rounded = Σ ⌈people in each team⌉; optimized = ⌈Σ people⌉, given to the teams with the largest fractions
Cost = wages × (1 + burden) + [hours above the limit × hourly rate × (1 + premium) + night hours × hourly rate × night premium] × (1 + burden) + coverage overtime (with burden) + freelancers (no burden) + holiday premium

Assumptions and limits

  • Indicative calculator. It gives an estimate to compare schedules and costs; it does not exactly reproduce each country’s laws, collective agreements or your company’s rules. Applicable labor laws and agreements must be evaluated and taken into account; this is the user’s responsibility. The calculator does not check legal limits.
  • On weekly schedules (5x2, 6x1), the week’s days off are consecutive and include the day the shift does not run. On cycle schedules (4x2, 6x2, 12/36, 2-2-3, Continental, 24/72), the calculator tests counting the closed day as a day off (with the 2nd day off before, after or alternating) or pausing the cycle, and uses the rule that needs fewer people. The result is a good arrangement, not necessarily the only or the optimal one.
  • Backup: in each team the calculator picks the cheapest mix of hiring, overtime by people on their day off (only if the shift’s hours fit within the daily overtime maximum, and within the maximum days per month) and freelancers (per day or per hour; automatic mode keeps at least one employee per position). Hours above the weekly limit use Monday’s %; night hours are those worked inside the window. Paid holidays use the holiday % on an average day’s position-hours.
  • The cost is an estimate to compare schedules: it does not include paid weekly rest rules, union scales and premiums, accruals beyond the burden entered, nor the cost of hiring and training.

Official sources and references

Frequently asked questions

What does this calculator do?

You enter when the company operates (days, hours and positions, or custom shifts) and how people work (schedule, hours per day, breaks). The calculator shows how many people each team needs with vacation and absences, whether every hour is covered, each person’s hours, overtime, payroll cost, a comparison of the ticked schedules and a 4-week calendar for each.

Does the calculator check whether the schedule is legal?

No. It is an indicative calculator: it gives an estimate to compare schedules and costs and does not exactly reproduce the law, collective agreements or your company’s rules. Applicable labor laws and agreements must be evaluated and taken into account; this is the user’s responsibility.

How is overtime counted?

Hours above the weekly limit (40 by default) are paid at the premium of each weekday, 50% by default. Daily overtime rules such as California’s (over 8 hours a day) are not modeled. You can also let people on their day off cover positions with overtime when that is cheaper than hiring.

Why round each team up, and what is the optimization?

People cannot be split. Rounding each team up always covers the calculation but adds up the fractions. The optimization rounds only the total and gives the people to the teams with the largest fractions; teams with one person less rely on people moving between teams or occasional overtime.

When do freelancers make sense?

When a few days need more people, such as Saturday. The calculator only uses freelancers where they are cheaper than hiring (wage with burden, vacation and absences), respects each freelancer’s maximum days per week and, in automatic mode, keeps at least one employee per position in each team.

What is the difference between fixed teams and rotation?

With fixed teams (default), each shift has its own team sized to its positions, and a person always starts at the same time. With rotation, teams change shifts (day, evening, night) and all are sized to the largest shift, which usually needs more people when shifts have different positions.

Which schedules can I compare?

5x2, 6x1, 4x2, 6x2, 12/36, 2-2-3, Continental, 24/72 and a custom week with hours for each day. Each has a suggested hours-per-day value that you can edit (7:20, 7h20, 7.5 or 720 all work). The comparison and calendars use the same operating hours and rules for all of them.

Related calculators

See all in Pay, cost & hours ›

How to plan shift schedules and estimate payroll cost

A shift schedule answers three questions for whoever pays the payroll: how many people the business needs, whether every hour is covered and what it costs each month. The answer changes a lot from one schedule to another, even with the same operating hours.

Start with operating hours, not with the schedule

First describe when the business operates and how many people must be working at the same time (positions). A plant open Monday to Saturday from 6:00 to 22:00 needs two shifts a day. Each shift has its own team; the schedule (5x2, 4x2, 2-2-3…) sets which days each person is off.

People cannot be split

With days off, vacation and absences, a team may need 6.3 or 6.7 people. Rounding each team up always covers the need; the optimization rounds only the total and shows the saving if one team has one person less, covering absences with people moving between teams or occasional overtime.

Overtime and freelancers instead of hiring

When only a few days need more people, paying overtime to someone on their day off or calling in freelancers can be cheaper than hiring. The calculator tests the options, keeps the cheapest and checks on a 4-week calendar that every position is covered.

The result is an estimate to compare schedules and costs. Before changing a schedule, check the labor laws, agreements and company rules that apply.