GATE NAT answers: is there a tolerance?

A GATE numerical answer is not marked against a general tolerance. It is marked against a range printed beside that one question in the official answer key, and that range is set question by question. Eighteen of the fifty previous-year papers hosted on this site carry the organising institute's own key, appended after the last question. Those eighteen keys hold 406 NAT rows. In 218 of them — 54 per cent, just over half — the same number is written on both sides of the word “to”, in the form “2 to 2”. For those questions, only the exact value scores. The other 177 state a genuine band, and the bands are nothing like a fixed width: the narrowest in these files spans 0.002, the widest spans 300,000. Advice to “round to two decimals” or to expect some fixed percentage of tolerance does not describe what these documents show.

Source: The 50 hosted paper files, parsed 18 September 2026, as on 18 September 2026

How many NAT questions accept one value, paper by paper

54 per cent is a count of these eighteen papers, not a forecast

Source: The 50 hosted paper files, parsed 18 September 2026, as on 18 September 2026

Where the range is written

The key is a table printed after the last question of the paper. In the 2018 files its header reads: “Q.No. Type Section Key/Range Marks”. Later keys reword the headings, and the 2020, 2022, 2023 and 2024 files carry an extra Session column, but the table holds the same things throughout: the question number, the session where one is given, the question type as MCQ, MSQ or NAT, the section as GA or the subject code such as CS, EC, EE, IN or BT, the accepted answer, and whether the question carried 1 mark or 2. For an MCQ, the answer column holds a letter. For a NAT question, that same column holds the range: twelve of the eighteen keys head it Key/Range, while the BT 2019 and the 2020 keys head it simply Key and print ranges in it just the same. There is no separate tolerance column. The range in that cell is the tolerance, and it belongs to that question alone.

Source: The 50 hosted paper files, parsed 18 September 2026, as on 18 September 2026

Real bands from these keys, tightest to widest

• EC 2020, question 54: “0.299 to 0.301”, a width of 0.002. No band in the eighteen keys is narrower.
• CS 2023, question 60: “2.374 to 2.376”, also 0.002 wide, and the only band in the whole CS 2023 key.
• CS 2018, question 15: “0.021 to 0.024”, a width of 0.003.
• IN 2022, question 64: “0.365 to 0.369”, a width of 0.004.
• EE 2018, question 54: “0.104 to 0.112”, a width of 0.008.
• EC 2022: nothing in that key is wider than 0.2, the width of question 34’s “5.5 to 5.7” and of three other rows.
• IN 2020: nothing in that key is wider than 2, the width of question 42’s “199 to 201” and of one other row.
• IN 2022, question 27: “870.0 to 880.0”, 10 wide, the widest in that key.
• EC 2020, question 17: “644 to 657”, 13 wide, the widest in that key — the same key that holds the 0.002 band above.
• BT 2018, question 55: “2900000 to 3200000”. That band is 300,000 wide and is the widest in any of the eighteen keys.

Source: The 50 hosted paper files, parsed 18 September 2026, as on 18 September 2026

The tightest and the widest are both real keys, published by the same examination, and the EC 2020 key holds a band of 0.002 and a band of 13 at the same time. Sign is part of the answer too: the EC 2018 key contains a value written “-0.5 to -0.5”, which is an exact-value key for a negative number. A handful of keys go further and accept two separate answers. In the IN 2018 key, question 12 reads “90 to 90 (or) -270 to -270” and question 14 reads “180 to 180 (or) -180 to -180”. The CS 2020 key gives “13.3 to 13.3 OR 13.5 to 13.5” at question 21, the IN 2020 key “2.5 to 2.5 OR 3.5 to 3.5” at question 25, and the EE 2022 key “188 to 192 OR 198 to 202” at question 56 and “675 to 700 OR 1725 to 1740” at question 63. The BT 2020 key, at question 53, accepts “48.50 to 49.50 OR 18521.20 to 18521.30”, and the CS 2023 key, at question 30, accepts “2 to 2 OR 4 to 4”. Eight NAT rows in the eighteen keys are written that way. Why any particular key is shaped as it is, these documents do not record, and this post does not guess.

Source: The 50 hosted paper files, parsed 18 September 2026, as on 18 September 2026

What the brochure instructs, and what it leaves to the key

The GATE 2027 Information Brochure sets out how a NAT answer must be entered on printed page 23. Three of its instructions there matter here. The answer is “a signed real number, which must be entered by the candidate using the virtual numeric keypad on the monitor (keyboard of the computer will be disabled)”. Then: “The stem or main body of the NAT question will indicate the number of decimal places that must be specified in the answer.” And candidates are “advised to round-off only at the end of the calculation and not at intermediate stages of the calculation”. Those instructions are about precision, not about tolerance. They tell you how to enter the number and how many decimal places the question wants; page 23 states no percentage of allowance and no blanket margin of any kind. The margin lives in the key, one question at a time. For GATE 2027 itself, the brochure says the answer keys will be displayed on the official website after the examinations, and that candidates may contest them during specified dates on payment of a fee, on printed page 27 — so the band for a 2027 question becomes readable only once that key is out.

Sources: GATE 2027 Information Brochure, p. 23, as on 18 September 2026; GATE 2027 Information Brochure, p. 27, as on 18 September 2026

One pattern across branches, stated as a count and no more

Read down the table and the CS rows look different from the EE and IN rows. The CS keys lean towards the exact value: across the four CS keys, 69 of the 81 NAT rows carry the same number on both sides while just 10 state a band, and CS 2020 does so in 20 of its 23. The EE and IN keys lean the other way: EE 2020 states an exact value in 4 of its 22 NAT rows, EE 2022 in 5 of 22, and IN 2022 in 9 of 26. That is an observation about eighteen files and it is offered as nothing else. These documents record no reason for it, so none is proposed here, and it should not be read as a statement about how any paper is set, about which branch is marked more generously, or about what any future paper will do. Its only practical use is local: a candidate working through the CS set will meet keys that mostly accept nothing but the exact number, and can practice accordingly, while a candidate working through EE or IN will meet more bands in these particular years.

Source: The 50 hosted paper files, parsed 18 September 2026, as on 18 September 2026

What this changes in the examination hall

NAT questions carry no negative marking — that rule is on printed page 4 of the brochure, and the full question-type and marking scheme is set out at /guide/gate-2027-exam-pattern-and-marking. So an attempt costs nothing. A blank NAT answer and a wrong one score the same zero, which is the argument for typing your best number every time. The cost sits somewhere else, and it is the part worth rehearsing. On a question whose key accepts one exact value, an answer that is right in method and wrong in the third decimal scores zero just as completely as an answer that is wrong throughout. That is not a penalty; it is the arithmetic of a zero-width band. It follows from the documents and from nothing else: the brochure says round off only at the end, and the keys show why that instruction has teeth. Two habits fall out of it. Carry the full precision through the working and round once, at the end. Type the number of decimal places the stem asks for, not the number you happen to have. Registration dates, the fee and eligibility are not covered here; they are on the GATE 2027 application checklist at /resources/gate-2027-application-checklist.

Sources: GATE 2027 Information Brochure, p. 4, as on 18 September 2026; GATE 2027 Information Brochure, p. 23, as on 18 September 2026; The 50 hosted paper files, parsed 18 September 2026, as on 18 September 2026

How to check any of this yourself

Source: The 50 hosted paper files, parsed 18 September 2026, as on 18 September 2026