To prepare for the CDS, learn the pattern first: three papers for IMA, INA and AFA (English, General Knowledge and Elementary Mathematics, 100 marks and two hours each) and two for OTA (English and General Knowledge). Then split your time by paper, practise on UPSC’s own papers, and start SSB preparation early, because the interview carries as many marks as the written test. This guide gives a six-month plan and a paper-wise booklist.
Facts about the examination come from UPSC’s CDS (II) 2026 notice, read on 12 October 2026.
The pattern you are preparing for
| Paper | For | Marks | Time | Standard |
|---|---|---|---|---|
| English | IMA, INA, AFA, OTA | 100 | 2 hours | About graduate level |
| General Knowledge | IMA, INA, AFA, OTA | 100 | 2 hours | About graduate level |
| Elementary Mathematics | IMA, INA, AFA only | 100 | 2 hours | Matriculation level |
- Objective papers; one-third of a question’s marks is deducted for each wrong answer, and blanks are free.
- The SSB carries 300 marks for IMA, INA and AFA and 200 for OTA, equal to the written marks.
- The notice says the General Knowledge paper includes current events, everyday science, the history of India and geography. Elementary Mathematics covers Arithmetic, Algebra, Trigonometry, Geometry, Mensuration and Statistics.
If you are aiming only for OTA, you can skip Mathematics. If you may also want IMA, INA or AFA, you cannot. Our OTA Chennai vs IMA Dehradun page helps you decide.
When to plan for
UPSC’s 2027 calendar lists CDS (I) 2027 on 11 April 2027, with notification on 2 December 2026 and applications closing on 22 December 2026. CDS (II) 2027 is on 19 September 2027, with notification on 12 May 2027 and applications closing on 1 June 2027. Dates can change. See CDS notification and exam dates for updates.
A six-month plan with SSB alongside
This plan is our own suggestion, not an official schedule. Adjust it to your college hours.
| Month | Written preparation | SSB preparation |
|---|---|---|
| 1 | Take one past paper as a diagnostic. Start NCERT Mathematics up to Class 10 and basic grammar. | Read how the SSB works. Start a daily newspaper habit and a simple fitness routine. |
| 2 | Finish Arithmetic and Algebra. Daily vocabulary. Begin General Knowledge notes: history and geography. | Learn the stages and the OLQs. Begin a personal diary of your own strengths, weak points and experiences. |
| 3 | Geometry, Mensuration, Trigonometry. Comprehension and error-spotting practice. Science notes. | Practise the picture story and group discussion with friends. |
| 4 | Statistics. Timed sectional tests. Current affairs notes. | Write practice TAT, WAT and SRT sets. Prepare honest answers about your own life. |
| 5 | Full-length timed papers every week; keep an error log. | Attend or hold mock group tasks. Practise lecturettes. |
| 6 | Revise error logs. Two papers a week, timed. Light revision of notes. | Mock interviews. Review your PIQ answers. |
Our guides on the SSB interview process, the PIQ form, the 15 OLQs and the SSB conference cover the board in detail.
Books, tagged to the paper they serve
These are real, widely available titles. We make no claim that any one is better than another. Start with NCERT and add one book per paper.
| Paper | Start with | Then, if you need more practice |
|---|---|---|
| English | High School English Grammar and Composition by Wren and Martin | Objective General English by S.P. Bakshi; Word Power Made Easy by Norman Lewis |
| General Knowledge | NCERT History, Geography and Science textbooks | A Brief History of Modern India by Rajiv Ahir (Spectrum); Certificate Physical and Human Geography by Goh Cheng Leong; Manorama Year Book for current events |
| Elementary Mathematics (not for OTA-only) | NCERT Mathematics textbooks up to Class 10 | Objective Arithmetic and Quantitative Aptitude for Competitive Examinations by R.S. Aggarwal |
Many “best books” lists come from the publishers that sell them, so treat a title’s presence on one as no proof of quality. Avoid pirated PDF mirrors; UPSC’s papers are free on its own site, indexed on our CDS previous year papers page.
Strategy points that pay off
- Accuracy over volume. The one-third penalty makes careless attempts costly.
- English is common to every academy. It is the one paper that every candidate takes, so build it daily.
- Mathematics is matriculation level. The notice says so, so it rewards speed and revision of school topics.
- Keep an error log and revisit it every week.
- Know the cut-off pattern. See our CDS cut-off page for UPSC’s published figures. They are a guide to the level, not a target.
Not sure how to fit this around a degree? Call or WhatsApp +91 70170 31757 for free counselling. Eligibility and syllabus details are in our CDS eligibility guide.
Paper-wise tips
- English (120 items in the 2026 (II) booklet). The notice says the paper tests understanding of English and workmanlike use of words. Practise error spotting, sentence improvement, vocabulary in context and comprehension passages, and time yourself on passages, which take the longest.
- General Knowledge (120 items). Current events, everyday science, the history of India and geography, as the notice lists. Make short notes by topic and revise them weekly. For current events, read a newspaper every day and note only what you can recall under pressure.
- Elementary Mathematics (100 items). Matriculation level. Speed matters: learn tables, squares, percentage and ratio shortcuts, and revise geometry theorems and mensuration formulas. Because the paper has 100 items in two hours, you have roughly a minute and a bit per item.
Mistakes we see candidates make
- Leaving SSB preparation until after the written result. The interview marks equal the written marks.
- Collecting many books and finishing none.
- Attempting every item without watching the one-third penalty.
- Ignoring English because it feels easy. It is the one paper every academy counts.
- Not reading the notice. The age window, the degree rule and the vacancy list are all in it, and our CDS eligibility guide summarises them.
Using mock tests
Start taking timed full papers about eight weeks before the examination. After each one, spend as long reviewing as you spent writing. Sort every error into three kinds: you did not know, you knew but slipped, or you ran out of time. Each needs a different fix. UPSC’s own papers are the best mock material, because they show the real level, and they are linked on our CDS previous year papers page.
FAQs
Questions parents ask us.
Can't find yours? Ask on WhatsApp; a counsellor usually replies within working hours.
Ask on WhatsAppCan I prepare for CDS in six months?
Many candidates plan for about six months. It depends on your starting point. The plan above is a suggestion, and UPSC sets no minimum preparation time.
Is Mathematics compulsory in CDS?
It is a paper for IMA, INA and AFA. OTA candidates take English and General Knowledge only.
Which books should a beginner use?
Start with NCERT, a grammar book such as Wren and Martin, and one practice book for arithmetic.
Should I prepare for the SSB after the written result?
We suggest starting earlier, because the SSB carries marks equal to the written test and tests habits that take time to build.
Is there negative marking in CDS?
Yes, one-third of the marks for each wrong answer.
What is the standard of the CDS Mathematics paper?
The notice says Matriculation level.
Preparing for the CDS and the SSB together? GS India Defence Academy runs classroom CDS coaching in Dehradun, with SSB-focused preparation, separate hostels for boys and girls and a mess. See the fee structure page for current options.
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