Last verified: 15 October 2026 (Thursday, morning). The exam structures, age windows and training academies below are CONFIRMED from the long-standing, publicly documented patterns of the UPSC NDA/CDS examinations and the Indian Air Force’s AFCAT — these frameworks have been stable for years. Exact age cutoffs, vacancy counts and physical standards change with every notification, so treat any number here as a guide and always check the current official notification (upsc.gov.in for NDA/CDS, afcat.cdac.in for AFCAT) before planning.
Walk through any Sainik School and ask a Class 12 cadet what comes next, and you will hear one word: NDA. But NDA is one of three major doors into an officer’s uniform — and the other two, CDS and AFCAT, open later in life and suit students the NDA window has already passed by. Parents hear these acronyms in coaching ads and parent groups and quietly wonder: are they the same exam? Is one a backup for the other? Does the uniform differ?
Here is the straight answer: all three routes end at the same place — a commission as an officer in the Indian Armed Forces. They differ in when you can walk in, who runs the exam, and which services and branches they feed. Understanding that early matters, because it changes how your family plans the years between Class 9 and graduation.
| NDA | CDS | AFCAT | |
|---|---|---|---|
| Full name | National Defence Academy examination | Combined Defence Services examination | Air Force Common Admission Test |
| Conducted by | UPSC, twice a year | UPSC, twice a year | Indian Air Force, twice a year |
| When you apply | After Class 12 (appearing students eligible) | After graduation (final-year students eligible) | After graduation (final-year students eligible) |
| Age window | 16.5–19.5 years | Roughly 19–25 (varies by academy) | 20–24 for flying branch; 20–26 for ground duty |
| Services covered | Army, Navy and Air Force | Army, Navy and Air Force | Air Force only (flying + ground duty branches) |
| Training academy | 3 years at NDA Khadakwasla (Pune), then 1 year at IMA / INA / AFA | IMA Dehradun (Army), INA Ezhimala (Navy), AFA Dundigal (Air Force), OTA Chennai | Air Force Academy, Dundigal |
| Commission type | Permanent Commission | Permanent (IMA/INA/AFA) or Short Service (OTA) | Short Service (flying); permanent options in ground duty |
| Women eligible | Yes (since 2021) | Yes (including OTA) | Yes (flying + ground duty) |
| Written syllabus level | Class 11–12 (maths + general ability) | Graduate level | Graduate level (plus EKT for technical branches) |
The single most useful row in that table is the first one that matters to you: NDA is the only door that opens at 17. CDS and AFCAT are the doors that open at 21. Everything else follows from that.
The NDA exam is conducted by UPSC twice every year and is the route most Sainik School families know best — for good reason. It is the only one of the three that a school student can take. The age window of 16.5 to 19.5 years means a typical cadet becomes eligible in Class 11 or 12, and written-exam success while still in school is common: in the current cycle alone, schools have been reporting remarkable tallies — Kalikiri’s 50 written-stage qualifiers, Ghorakhal’s 44, Nalanda’s 23.
The written paper has two parts — Mathematics and a General Ability Test covering English, science, history, geography and current affairs — followed by the five-day SSB interview for those who clear it. Selected cadets spend three years together at the National Defence Academy in Khadakwasla, Pune, training alongside future Army, Navy and Air Force officers, before one more year at their service academy: IMA Dehradun for the Army, INA Ezhimala for the Navy, or AFA Dundigal for the Air Force. The endpoint is a Permanent Commission.
Who it suits: students who are certain early, and families who can support intensive Class 11–12 preparation alongside board exams. If your child is in a Sainik School, the school’s own coaching system is already doing most of this work.
The Combined Defence Services examination, also run by UPSC twice a year, is the NDA’s older sibling. Same conductor, different audience: graduates (final-year students can apply). It feeds four academies — IMA Dehradun and OTA Chennai for the Army, INA Ezhimala for the Navy, and AFA Dundigal for the Air Force.
The key distinction inside CDS is commission type. IMA, INA and AFA entries lead to Permanent Commission; OTA Chennai entries lead to Short Service Commission (10 years, extendable, with a permanent-commission option later). OTA is also the route through which many women officers have historically entered the Army, though women are now eligible across entries.
Who it suits: students who missed or aged out of the NDA window — which is most college students — and anyone who wants to keep all three services on the table after graduation. If your child clears AISSEE but not NDA in school, CDS is not a consolation prize; it is the main road most officers actually travel.
AFCAT is run by the Indian Air Force itself, twice a year, and it is the only one of the three limited to a single service. In exchange, it offers something the others don’t: entry into the Flying Branch — the pilot’s route — alongside Ground Duty branches (technical and non-technical). The written test is graduate-level, and technical-branch candidates additionally take the Engineering Knowledge Test (EKT).
The age bands are narrower than CDS: roughly 20–24 for the flying branch and 20–26 for ground duty. Training happens at the Air Force Academy in Dundigal. Flying branch entries carry Short Service Commission; ground duty branches offer permanent commission pathways.
Who it suits: graduates with a clear Air Force calling — especially flying-branch aspirants, for whom AFCAT (alongside CDS’s AFA entry and the NDA air force wing) is one of the very few doors that exist.
Forget “which is best” — ask “which is open” and “which fits the timeline”:
One honest note for parents: no route is “easier.” NDA faces the largest applicant pool; CDS and AFCAT face smaller pools but test graduate-level depth. The students who succeed in any of the three share one trait — they started preparing for their route on time, instead of mourning the one that closed.
What is the difference between NDA, CDS and AFCAT?
NDA is the only route that starts right after Class 12, run by UPSC for the Army, Navy and Air Force together. CDS is for graduates and is also run by UPSC, feeding the Army, Navy and Air Force academies plus OTA Chennai. AFCAT is run by the Indian Air Force itself, for graduates joining the Air Force’s flying and ground duty branches.
Can a Sainik School student appear for NDA while still in school?
Yes. NDA’s age window (16.5 to 19.5 years) means most Sainik School cadets become eligible in Class 11 and 12, and many qualify the written exam while still on campus — schools like Kalikiri, Ghorakhal and Nalanda regularly report dozens of written-stage qualifiers each year.
Which is easier: NDA, CDS or AFCAT?
None of the three is easy — all are competitive national exams with an SSB interview stage. Broadly, NDA competition is intense because the entry pool is huge; CDS and AFCAT competition is narrower but the syllabi assume graduate-level knowledge. The honest answer: the route that matches your current education stage is the best one.
Can girls join through NDA, CDS and AFCAT?
Yes, women can now join through all three routes. NDA opened to women in 2021, and our complete guide covers the girls’ path in detail. CDS offers entry through OTA Chennai for women, and AFCAT recruits women for both flying and ground duty branches of the Air Force.
Do NDA cadets get the same commission as CDS and AFCAT officers?
Yes — all three routes lead to a commission as an officer in the Indian Armed Forces. NDA cadets earn a Permanent Commission, CDS IMA/INA/AFA entries earn Permanent Commission, CDS OTA entries earn Short Service Commission, and AFCAT flying branch entries earn Short Service Commission with permanent commission options for ground duty branches.
What should a Class 9 Sainik School aspirant do right now about NDA?
Nothing NDA-specific yet — and that is good news. Clearing AISSEE and getting into a Sainik School is itself the best NDA preparation available: the routine, the academics, and the written-exam coaching cadets receive in Class 11 and 12. Focus on the entrance in front of you first.
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