NDA, CDS and AFCAT: A 6-Month Defence Study Plan

Prepare for the National Defence Academy (NDA), Combined Defence Services (CDS) and Air Force Common Admission Test (AFCAT) as one shared core plus a small exam-specific layer. English, general knowledge and general science carry across all three, so the only real difference is mathematics, and the SSB interview stage is common to all of them.

The NDA and Naval Academy Examination and the CDS Examination are conducted by the Union Public Service Commission (UPSC). AFCAT is conducted by the Indian Air Force (IAF). All three are written tests followed by a Services Selection Board (SSB) interview, called the Air Force Selection Board (AFSB) for Air Force candidates.

All three apply a penalty for wrong answers, and each paper has its own duration. Eligibility, entry routes, the number of attempts and the subject requirements at Class 12 differ by exam and by branch, and they change. Read them from the current notification on the official UPSC website and the Indian Air Force careers portal rather than from any preparation page.

Which defence exam fits my stage?

NDA is the entry route available at the Class 12 stage; CDS and AFCAT are graduate-entry routes. That single fact settles most of the question, because you cannot choose an exam you are not yet eligible for.

In practice the sequence works like this. A school student prepares for NDA, and because the academic ground is the same, that preparation is not wasted if they later sit CDS or AFCAT as a graduate. A final-year undergraduate prepares for CDS and AFCAT together, since the two run on similar content with different papers. A candidate from an engineering background who wants a technical Air Force branch adds the Engineering Knowledge Test (EKT) to AFCAT. The Central Armed Police Forces (CAPF) Assistant Commandants examination is a separate route with its own pattern, worth knowing about but not worth preparing for simultaneously. If you are also applying to uniformed recruitment outside the armed forces with a physical efficiency test, the routine in the RRB Group D study plan is closer to what that needs.

What do NDA, CDS and AFCAT actually consist of?

Each exam is a written test whose sections map onto the same four skills: mathematics, English, general knowledge and reasoning. What differs is the level and the weight.

Confirm question counts, durations and the exact penalty for wrong answers against the current notification, since these are revised from time to time.

How should I split time between maths and the General Ability Test?

Give mathematics daily practice and the General Ability Test steady reading, because they improve on different timescales. Mathematics is a skill and moves slowly; general knowledge is largely recall and responds to short, frequent contact.

The marks tempt candidates the wrong way. The NDA General Ability Test carries twice the marks of the mathematics paper, so it looks like it deserves twice the time. But GAT marks are cheaper per hour, while a weak mathematics paper is what actually stops a strong overall score, and it cannot be repaired in the final month. An example allocation is about 40 percent of study time on mathematics and 60 percent spread across English, general science, general knowledge and current events, with the mathematics share rising if your mock accuracy there is the weaker of the two.

For CDS, the same logic applies at a lower level: Elementary Mathematics is matriculation content, so the work is speed and accuracy rather than new concepts. For AFCAT, numerical ability and the reasoning section both reward drilled patterns, and the reasoning ability preparation plan covers the question types directly.

How do I build general science and general knowledge from school textbooks?

Build it from NCERT science and social science textbooks for Classes 6 to 10 first, then add current events. The General Ability Test and the CDS General Knowledge paper both ask at roughly that level, and a school textbook gives you the whole syllabus in a readable form instead of a 900-page compendium you will not finish.

A workable routine:

1. Read one chapter of school-level science or social science per study day, in syllabus order rather than by interest.
2. Write ten one-line recall prompts from each chapter as you read, not afterwards.
3. Answer the previous three days of prompts before starting anything new.
4. Keep a fixed 20-minute daily slot for current events from one newspaper or one monthly compilation.
5. Consolidate the week's current events into a single page each weekend.
6. Revisit each chapter's prompts after a week and again after a month, with the review dates on the planner calendar so an overdue set is visible.

The single-source discipline and the monthly consolidation habit are set out in more detail in the current affairs preparation strategy for government exams. Spacing those reviews rather than rereading is what makes a year of general knowledge survive to exam day; the practical version is the spaced repetition revision timetable.

How do I prepare English once for all three exams?

Prepare English once, as a single skill set, and let each exam draw from it. All three test the same ground: vocabulary in context, grammar and error spotting, sentence improvement, ordering of sentences and reading comprehension. Only the packaging differs.

That means one daily English block serves everything: a short vocabulary set, one grammar topic per week worked through error-spotting questions, and one comprehension passage under a timer. Candidates waste months buying an NDA English book, a CDS English book and an AFCAT English book and doing the first forty pages of each. Choose one grammar source, one vocabulary method and the previous year papers of all three exams for practice.

What does a 6-month defence exam study plan look like?

The table below is an example six-month track for a student with two to three hours on weekdays and five to six at the weekend. Adapt it to your own baseline and to which exam comes first.

No new topic enters after month five. The last month is timing, revision and error repair.

How do I keep this plan alive during board exams or college?

Shrink the plan rather than suspending it. A suspended plan loses mathematics accuracy and current awareness fastest, and both take longer to rebuild than they took to maintain.

During a board exam or a college examination period, drop to a minimum viable version: one 30-minute mathematics set and one 15-minute current events slot per day, and nothing else. That is enough to keep the two decaying skills alive. Everything else resumes afterwards. The same principle of a reduced core rather than a pause is set out in the guide to handling Class 12 boards alongside entrance preparation, and the recovery routine for a genuinely missed stretch is in the study plan catch-up method.

When should I start SSB or AFSB preparation?

Start light from the beginning and serious only after the written exam. The SSB is a multi-day assessment and the written test is a knowledge test; they reward different preparation, and the interval between the result and the interview is long enough for focused work.

Light work from day one means habits that help regardless of the outcome: daily current affairs, regular physical activity, speaking in groups, and reading enough to hold an informed conversation on a national issue. Serious work after the written exam means understanding the format of the screening stage and the testing stage, practising the psychological tests to time, and rehearsing a personal interview honestly rather than with rehearsed answers. Do not buy SSB material in month one of a six-month plan; it displaces the studying that gets you to the interview in the first place.

How do I use previous year papers and mocks across three exams?

Solve previous year papers exam by exam, but analyse them as one dataset. Topic frequency in NDA mathematics, CDS Elementary Mathematics and AFCAT numerical ability overlaps enough that a weakness in one shows up in all three.

Sit full-length papers under real timing from month three, one per fortnight at first and weekly in the last month. After each, record every wrong answer with a cause: concept not known, method misapplied, calculation slip, misread question, or time pressure. Count the causes weekly and let the largest count decide the next week's focus. The full routine is in the mock test error log method, and the method for reading a paper for what the exam asks rather than for your own score is in the previous year question paper analysis guide. Fix the paper dates in MyStudyPlanner at the start of the six months so they are commitments, not intentions.

Common mistakes in defence exam preparation

• Chasing the General Ability Test because it carries more marks, and arriving at the exam with a weak mathematics paper.
• Reading a thick general knowledge compendium instead of school textbooks that actually match the level.
• Buying separate English material for each exam and finishing none of it.
• Starting SSB preparation in month one and the written syllabus in month four.
• Suspending the plan entirely during board or college exams instead of shrinking it.
• Attempting recklessly in exams that penalise wrong answers, having never practised an attempt rule.

Frequently Asked Questions

Which defence exam should I prepare for after Class 12?

The National Defence Academy and Naval Academy Examination is the entry route available at the Class 12 stage, while the Combined Defence Services Examination and the Air Force Common Admission Test are graduate-entry routes. A school student therefore prepares for NDA now and keeps CDS and AFCAT as later attempts, since the academic content overlaps heavily. Entry-specific eligibility is set in each official notification.

Can I prepare for NDA, CDS and AFCAT at the same time?

Yes, because the three share English, general knowledge and general science, and differ mainly in mathematics. NDA mathematics is at senior secondary level, CDS Elementary Mathematics is at matriculation level, and AFCAT tests numerical ability rather than advanced maths. Build one shared core of English and general awareness, then add a short exam-specific maths track for whichever exam is nearest.

How should I split time between Mathematics and the General Ability Test?

Mathematics needs daily practice because it is a skill that moves slowly, while the General Ability Test rewards steady reading and revision because it is largely knowledge. An example split is about 40 percent of study time on mathematics and 60 percent across English, general science, general knowledge and current events, with the maths share rising if your mock accuracy in that paper is the weaker of the two.

When should I start SSB interview preparation?

Start light work on it from the beginning and serious work only after the written exam is over. The written paper and the Services Selection Board assessment test different things, and there is a gap between the two that is long enough for focused preparation. Early on, keep to habits that help anyway: daily current affairs, physical fitness, group activities and speaking practice.

How many hours a day do I need for defence exam preparation?

Two to three focused hours on a school or college day and five to six at the weekend is a workable target across a six-month plan. Consistency matters more than volume: a daily mathematics set and a fixed current affairs slot beat occasional long sessions, because both mathematics and general awareness decay quickly when left alone for a week.

Your next step this week

Confirm from the official notification which exam you are actually eligible for right now, then build those six months in MyStudyPlanner with the full-length paper dates fixed from month three onwards. Start today with one mathematics set and one school science chapter, and put the recall prompts for both on the calendar for review in three days.