NDA vs CDS: Training, Pay and Which Route Suits You

NDA and CDS both lead to a commissioned officer career in the Army, Navy or Air Force, and both use the SSB selection process — but they start from different educational stages, take genuinely different amounts of time to reach commissioning, and (in CDS's case specifically) can lead to a different type of commission depending on which academy you target. This guide compares them directly.

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For full detail on either exam, see our NDA guide and CDS guide.

Quick Comparison

Eligibility: Different Starting Points

The most basic difference is when you can apply: NDA is open right after Class 12th (roughly 16.5–19.5 years), while CDS requires a completed or final-year degree (roughly 19–25 years, varying by academy). This isn't just a timing difference — it means NDA and CDS aren't really substitutes for each other at the same life stage; NDA is a decision you make in school, CDS is a decision you make in or after college.

Qualification requirements also differ in an important way: NDA's Navy/Air Force wings require Class 12th with Physics, Chemistry and Mathematics, while CDS's equivalent academies have different, more specific requirements — INA (Navy) requires an Engineering degree specifically, not just a science background, while AFA (Air Force) accepts either a PCM-based degree or a B.E./B.Tech. CDS's IMA and OTA, like NDA's Army wing, accept a degree in any discipline.

Exam Pattern: NDA Is Uniform, CDS Varies by Academy

NDA has one exam structure regardless of which wing you're targeting — Mathematics (300 marks) and General Ability Test (600 marks), totalling 900 marks for everyone. CDS varies: IMA, INA and AFA aspirants write three papers (English, GK, Elementary Mathematics) for 300 marks, while OTA aspirants skip Mathematics entirely, writing only English and GK for 200 marks. If you're weak in Mathematics specifically, CDS-OTA is the only route among these that doesn't test it at all — NDA (all wings) and CDS-IMA/INA/AFA all include a Mathematics paper.

Training Length: The Biggest Practical Difference

This is where NDA and CDS diverge most in real time commitment. NDA candidates train for three years at NDA itself (jointly across all three services) plus a further year at their service-specific academy — roughly four years total before commissioning, though this includes earning a Baccalaureate degree along the way. CDS candidates go directly into academy-level training: 18 months at IMA, roughly 22 weeks at INA, 52–74 weeks at AFA (depending on branch), or just 49 weeks at OTA — meaningfully shorter than NDA's total training period, since CDS candidates already arrive with a degree rather than needing one along the way.

In practical terms: an NDA candidate starting at 17 and an CDS candidate starting at 22 (after a 3-year degree) can end up commissioning around a similar age, despite starting from very different points — NDA's longer training roughly offsets CDS's later start.

Commission Type: Where CDS Adds a Real Choice

NDA leads to a Permanent Commission across all three wings — a full career by default. CDS offers a choice: IMA, INA and AFA (depending on branch) also lead to Permanent Commission, but OTA specifically leads to a Short Service Commission — a fixed-tenure commitment rather than an automatic full career (though extension or conversion options can exist depending on policy at the time). NDA doesn't offer an equivalent Short Service option — if you specifically want a shorter initial commitment with an officer rank, CDS-OTA is the route that offers it, not NDA.

Salary: Identical

Once commissioned, pay is the same regardless of route: Pay Level 10 (₹56,100 basic pay) plus Military Service Pay, whether you came through NDA or any CDS academy. See our Defence Salary guide for the full breakdown — salary isn't a factor in choosing between NDA and CDS.

Which Should You Choose?

If you're currently in or approaching Class 12th and are certain about a defence career, NDA is the earlier, more direct route — accepting a longer training commitment (about four years) in exchange for starting immediately and gaining broad tri-service exposure during the joint NDA years. If you're already pursuing or have completed a degree, CDS is the natural route, with training length and commission type depending on which academy you target — IMA/OTA for any degree, INA specifically for engineering graduates, AFA for PCM-background or engineering graduates. If you specifically want a shorter service commitment rather than a full career by default, CDS-OTA is the only option between these two that offers that.

There's no strict "better" here — they suit different educational stages, and many candidates who miss NDA (or decide on a defence career only after starting a degree) simply move to CDS instead, rather than viewing it as a lesser alternative.

Frequently Asked Questions

Is NDA better than CDS?

Neither is objectively better — NDA suits Class 12th-pass candidates ready to commit early with a longer training path; CDS suits graduates, with training length and commission type varying by academy. Salary is identical either way.

Which is easier, NDA or CDS exam?

Not reliably comparable — NDA has one exam structure for everyone, while CDS varies by academy (with OTA skipping Mathematics entirely). "Easier" depends on your own strengths and which specific academy/wing you're comparing against.

Can I do CDS if I didn't clear NDA?

Yes — NDA and CDS are entirely separate exams with separate applications. Missing or not attempting NDA doesn't affect CDS eligibility, provided you meet CDS's own age and qualification requirements as a graduate.

Which takes longer to become a commissioned officer, NDA or CDS?

NDA's total training (roughly four years: three at NDA plus one at the service academy) is generally longer than CDS's academy-only training (18 months at IMA, down to 49 weeks at OTA) — though CDS candidates start later, since they need a degree first.

Does CDS offer a Short Service Commission like some other entries?

Yes, specifically through OTA — a fixed-tenure commission rather than an automatic full career. NDA doesn't offer an equivalent Short Service route; all NDA-commissioned officers get a Permanent Commission.

Is the salary different between NDA and CDS?

No. Both lead to the same starting Pay Level 10 basic pay plus Military Service Pay once commissioned, regardless of which route or academy you came through.

In Summary

NDA and CDS aren't competing options for the same candidate at the same time — they're sequential opportunities tied to your educational stage, with NDA offering an earlier start and longer training, and CDS offering a faster path to commission (but only after completing a degree) along with OTA's unique Short Service option. Choose based on where you are in your education and how much training time you're prepared to commit, not on which one is generically "better."

Sources

• Pay levels and entry pay: 7th Central Pay Commission report, Pay Matrix