How many timetable periods should an IB HL or SL subject receive each week?

There is no universal weekly period number because schools use different lesson lengths, cycles, and numbers of effective teaching weeks. The IB recommends 240 teaching hours for HL and 150 hours for SL across the course. Coordinators should convert those hours into periods using the actual lesson duration and subtract weeks lost to holidays, examinations, and school events. For example, across 64 effective weeks, a 50-minute timetable needs 288 HL periods and 180 SL periods. A small additional allocation is advisable so predictable disruptions do not create an instructional shortfall.

Can an IB school teach an SL subject entirely in DP1?

Yes, current DP regulations allow up to two SL subjects to be taught and assessed after the first year when circumstances require this arrangement. Students taking those assessments use the anticipated registration category. It should not be treated as the default structure because DP courses are designed to benefit from concurrency and sustained learning. All HL subjects, the core, and at least one SL subject must continue across both years. Language ab initio and pilot subjects must also be taught throughout the two-year programme.

Should TOK be placed in the regular school timetable?

TOK should receive a dependable allocation within the school's planned instructional programme. The course is designed for 100 teaching hours, so occasional workshops alone are unlikely to provide adequate time. Regular lessons support sustained discussion, integration with the academic subjects, the exhibition, and the TOK essay. Schools may add intensive workshops near assessment milestones, but these should complement rather than replace continuing instruction. Timetabling TOK across both years also supports the DP principle of concurrency.

How much timetable time should a school allocate to CAS?

CAS is not defined as a conventional subject with a fixed number of classroom hours. Students are expected to participate regularly over an extended period, normally at least 18 months, rather than collect an old-style total of hours. Schools should nevertheless schedule enough contact time for induction, planning, monitoring, reflection, and CAS project support. Advisory periods or recurring core sessions often work better than treating CAS as a weekly academic lesson. The schedule must also leave students enough time outside lessons to undertake authentic creativity, activity, and service experiences.

What is the best way to reduce clashes between popular IB subject combinations?

Collect provisional student choices before fixing the option blocks and turn those choices into a subject conflict matrix. Subjects frequently chosen together should normally be placed in different blocks, while rare combinations should be reviewed individually. Coordinators should also distinguish essential university prerequisites from preferences that have acceptable alternatives. Combined HL and SL teaching, parallel classes, online provision, or carefully chosen anticipated SL courses can resolve some conflicts. Every student's complete programme should be generated and checked before the option structure is published.

How often should an IB DP timetable be reviewed?

The timetable should be checked formally before publication, after enrolment stabilizes, at the end of DP1, and before the main DP2 assessment period. Coordinators should also monitor delivered teaching hours each term because cancellations and school events accumulate gradually. Reviews should include subject access, teacher workload, room use, TOK and core provision, and student free periods. The assessment calendar needs more frequent review, ideally monthly with subject leaders, because deadlines move more often than lesson blocks. A clear change-control process prevents local adjustments from creating conflicts elsewhere in the programme.

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IB DP Timetabling: A Two-Year Plan That Works

IB Coordinators Program Management IB Study Guides

• 3 Oct 2026•11

IB DP Timetabling: A Two-Year Plan That Works

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IB DP Timetabling: A Two-Year Plan That Works | RevisionDojo

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IB DP Timetabling: A Two-Year Plan That Works

IB Coordinators Program Management IB Study Guides

• 3 Oct 2026•11

Effective IB DP timetabling starts with programme requirements, not with a generic secondary-school timetable. Coordinators must provide sufficient HL and SL teaching time, preserve concurrency across two years, accommodate the DP core, and offer viable subject combinations without creating an unsustainable workload.

The most reliable approach combines three plans: a two-year curriculum map, a repeating weekly or fortnightly timetable, and a whole-cohort assessment calendar. A schedule can appear compliant yet fail when teaching hours disappear through examinations, holidays, trips, deadlines, or staffing constraints.

Start with the IB programme requirements

Diploma students normally study three HL subjects and three SL subjects, although four HL subjects are permitted. The IB recommends 240 teaching hours for each HL subject and 150 teaching hours for each SL subject.

These are recommended teaching hours rather than universal statutory minimums. Schools should still plan around them because subject courses are designed for that instructional time, and programme evaluation considers whether the schedule supports effective delivery.

For a standard three-HL and three-SL diploma, subjects require 1,170 teaching hours. Four HLs increase the total to 1,260 hours, so approval should depend on student workload, staffing, and where the additional 90 hours will fit.

The official IB Diploma Programme overview places six subject groups alongside theory of knowledge (TOK), the extended essay (EE), and creativity, activity, service (CAS). The core must therefore be planned as part of the programme, not left for students to complete around six subjects independently.

Convert hours into timetable periods

Calculate the effective teaching weeks remaining after holidays, orientation, examinations, reporting days, trips, and predictable interruptions. Then use:

\text{required periods}=\frac{\text{recommended hours}\times60}{\text{period length in minutes}}

Suppose a school has 64 effective teaching weeks, 50-minute periods, and a 10-day cycle. This produces 32 cycles.

Component	Recommended time	Periods required	Allocation per cycle
One HL subject	240 hours	288 periods	9 periods
One SL subject	150 hours	180 periods	About 6 periods
TOK	100 hours	120 periods	About 4 periods

Six SL periods provide 160 hours, creating a useful buffer. Assemblies, mock examinations, closures, and teacher absence can all reduce delivered time.

Run the calculation separately for DP1 and DP2. DP2 frequently has fewer teaching weeks because formal examinations begin before the ordinary school year ends, so an equal annual allocation may still leave courses short.

Build option blocks from student demand

The main scheduling problem is creating option blocks that permit as many valid programmes as possible while respecting staffing, rooms, and class viability. Begin with provisional student selections early enough to influence recruitment and staffing.

Record each requested subject, level, class size, university prerequisite, and acceptable alternative. A conflict matrix can then show how often each pair of subjects appears within the same proposed diploma.

Use this evidence to:

separate subjects frequently selected together
protect educationally important combinations
identify programmes that the current blocks cannot accommodate
compare the effect of opening or closing classes
distinguish timetable conflicts from staffing limitations

Test every proposed diploma before publishing the blocks. A neat structure is unsuccessful if it prevents common pathways such as Biology HL with Chemistry HL or Economics HL with Mathematics: analysis and approaches HL.

Schools cannot guarantee every possible combination. Publish fair decision rules, consult affected families, protect documented university prerequisites where feasible, and record why exceptions were approved or declined.

Resolve HL and SL constraints

Many subjects contain shared HL and SL content, but HL requires substantially more teaching time. Schools usually choose among three models.

Combined classes with HL extension

HL and SL students study common content together, with additional lessons scheduled for HL. This is efficient for small enrolments when the subject guide supports a coherent shared sequence. It is less effective when level-specific content diverges or the teacher must alternate constantly between incompatible objectives.

Separate HL and SL classes

Separate classes simplify pacing and assessment but require more staff and timetable space. They are appropriate when enrolment is sufficient, level-specific content is substantial, or mixed teaching reduces effective instructional time.

Shared block with supervised study

The whole class occupies a common block, but SL students leave during HL extension for supervised study, EE work, or another planned responsibility. Whichever model is used, count the minutes purposefully taught at each level rather than assuming attendance equals instructional time.

Protect concurrency across both years

The DP is intended as a concurrent programme. Under the current general regulations for the Diploma Programme, all HL subjects, the core, and at least one SL subject must be taught across both years.

When circumstances require it, up to two SL subjects may be completed and assessed after DP1 as anticipated subjects. Language ab initio and pilot subjects must run across both years. Since compression concentrates teaching and assessment, schools should check the examination session, student readiness, teacher capacity, and first-year workload before using anticipated entry.

Timetable TOK, EE, and CAS explicitly

Theory of knowledge

TOK is designed for 100 hours and should not be reduced to occasional assemblies. Regular lessons support discussion, connections with subjects, the exhibition, and the 1,600-word essay described on the official TOK page.

Schools may front-load some TOK teaching in DP1 and reserve focused essay support for DP2. Students should nevertheless continue experiencing TOK across the programme.

Extended essay

The EE does not require a daily class, but students need structured access to supervisors, research instruction, reflection meetings, and protected writing time. Provision might include fortnightly core periods, library workshops, conference windows, and longer writing sessions.

Place subject allocation, research-question approval, reflections, draft feedback, final submission, and the viva voce on one central calendar. A common framework prevents supervisors from creating incompatible schedules.

Creativity, activity, service

CAS is not a fixed-hour classroom subject. Students should participate regularly for at least 18 months, undertake experiences across creativity, activity, and service, and complete at least one CAS project. This replaces the outdated idea that CAS is satisfied by accumulating a prescribed number of hours.

Schools still need contact time for induction, planning, monitoring, and reflection. Advisory periods, coordinator meetings, project blocks, and checkpoints provide oversight while most CAS experiences occur outside lessons.

Coordinate the assessment calendar

A viable weekly timetable can still create overload if departments set major deadlines independently. Build a two-year calendar covering IAs, oral assessments, performances, fieldwork, science projects, the EE, TOK assessments, mock examinations, university applications, and CAS checkpoints.

Useful workload rules include:

no more than two substantial final submissions in one week
separation between draft and final deadlines
protected mock-examination and revision periods
internal deadlines before official submission dates
contingency time for authentication, uploading, moderation samples, and absence

Review this calendar monthly with subject leaders. RevisionDojo's explanation of how the IB manages workload across subjects can help communicate why coordinated deadlines matter.

Audit and review the timetable

Before publication, complete six checks:

Compliance: Hours, concurrency, TOK, and core access.
Students: Individual clashes, excessive gaps, and demanding lesson sequences.
Staff: Workload, planning time, part-time availability, and single-teacher dependencies.
Facilities: Laboratories, specialist rooms, computers, and capacity.
Assessment: Peak workload periods across the cohort.
Resilience: Enrolment changes, staff departure, or an unviable class.

Subject teachers should inspect the draft because scheduling software cannot judge course sequencing or laboratory requirements. Review delivered hours each term, complete a fuller audit between DP1 and DP2, and establish an early cut-off for level or subject changes.

For student support, schools can share RevisionDojo's standard IB weekly schedule, full timetable organization guide, and explanation of the coordinator's role. These resources supplement rather than replace the school's official calendar.

Conclusion

Strong IB DP timetabling balances programme requirements, subject access, staffing, facilities, assessment pressure, and student wellbeing. Calculate allocations from effective teaching weeks, build blocks from real student combinations, timetable the core explicitly, and audit both lessons and deadlines before publication.

RevisionDojo's IB resources and study tools, Questionbank, and exam timetable guidance can help students turn the school's provision into structured independent practice.