IELTS Writing Score Calculator: How the Four Criteria Become One Band

Your Writing band is not a judgement someone makes at the end. It is arithmetic performed on four numbers, and the arithmetic is public. If you know your four criterion scores, you can compute the same band the examiner reports, by hand, in under a minute.

This page writes out every step. Work through it with your own numbers.

Step one: four criteria, whole bands only

Each task is marked against four criteria, each on the nine band scale.

For Task 2 they are Task Response, Coherence and Cohesion, Lexical Resource, and Grammatical Range and Accuracy. For Task 1 the first one is called Task Achievement instead, because the job is different: describing data or writing a letter rather than arguing a position. The other three are the same.

The important detail for the arithmetic is that criterion scores are whole numbers. An examiner gives you a 6 or a 7 on Lexical Resource, never a 6.5. Half bands appear only after the averaging, never before it. Any tool or teacher reporting 6.5 for a single criterion is not following the official scale.

Step two: average the four, then round

Add the four criterion scores and divide by four. Then round the result to the nearest half band.

Because you are averaging four whole numbers, the result can only ever end in .0, .25, .5 or .75. There are no other possibilities, which is what makes the rounding rule simple to state.

Take the .25 case properly, because it is the one that surprises people. Criteria of 7, 6, 6, 6 sum to 25. Divided by four that is 6.25. The official convention rounds .25 up, so the reported band is 6.5, not 6.0.

That single rule is worth half a band on a quarter of all possible score combinations. If you have ever seen a practice tool report 6.0 for those criteria, it was rounding the other way, and it was wrong.

The .75 case runs the same direction. Criteria of 7, 7, 7, 6 sum to 27, an average of 6.75, and the reported band is 7.0.

Step three: combine the two tasks

Task 2 is weighted twice as heavily as Task 1. The formula is:

overall = (task 1 band + task 2 band + task 2 band) / 3

Written another way, add your Task 1 band to double your Task 2 band, then divide by three. Round the result to the nearest half band again.

Here is a full worked example, start to finish.

Task 1. Task Achievement 6, Coherence and Cohesion 6, Lexical Resource 5, Grammatical Range and Accuracy 6. Sum is 23. Average is 5.75. Rounds up to 6.0.

Task 2. Task Response 7, Coherence and Cohesion 6, Lexical Resource 6, Grammatical Range and Accuracy 6. Sum is 25. Average is 6.25. Rounds up to 6.5.

Overall. Task 1 contributes 6.0. Task 2 contributes 6.5 twice, which is 13.0. Total 19.0, divided by three is 6.33. The nearest half band is 6.5.

What this tells you about where to spend your time

Once the arithmetic is in front of you, two things become obvious.

Task 2 is worth twice Task 1. Raising Task 2 by a full band moves your overall band by about 0.67. Raising Task 1 by a full band moves it by about 0.33. If your preparation time is limited and your two tasks are roughly level, Task 2 is where the same effort buys more.

Your weakest criterion is the cheapest one to fix. Because the four are averaged, one criterion sitting a band below the others is dragging the average down by a quarter of a band, and a quarter of a band is often exactly the distance between two reported half bands. Consider a candidate at 7, 7, 7, 5. Sum 26, average 6.5. Lifting only that last 5 to a 6 gives sum 27, average 6.75, reported 7.0. One criterion, half a band on the certificate.

The same candidate lifting an existing 7 to an 8 also reaches sum 27. But moving a criterion from 5 to 6 is a smaller distance in real writing skill than moving 7 to 8, and it usually has a clearer cause: missing articles, a word count under the minimum, no paragraph breaks, one register error in a letter.

A table you can read your own numbers off

Four whole criterion scores, so the sum runs from 4 to 36. Here is the middle of the range, which is where most candidates sit.

Notice the pattern in the right hand column: sums 25 and 26 both report 6.5, and sums 27 and 28 both report 7.0. Two different sums land on the same band, and one point of sum can be the whole difference between two bands. That is why a single criterion matters as much as it does.

Two things a calculator cannot do for you

The arithmetic is exact. The four numbers going into it are not, and that is the honest limit of every scoring tool including this one.

An examiner reads your answer against the public band descriptors and decides that your Lexical Resource is a 6 rather than a 7. That decision is a judgement about your writing. The averaging that follows is mechanical, and any calculator gets it right. Nothing that gets the arithmetic right is thereby getting the judgement right.

The second thing: an underlength answer is penalised before the arithmetic starts. Task 1 has a 150 word minimum, Task 2 has 250. Falling short affects Task Achievement or Task Response directly, so the effect is already inside the four numbers by the time you average them.

What to do today

Take your last practice answer, or your last marked mock. Write the four criterion numbers on a line, sum them, and look them up in the table above. Then ask which single number is lowest and what it would take to raise that one by a point. That is your next week of study, and it is a much more specific plan than "improve my writing".

If you do not have four criterion numbers to start from, Bandly will produce an estimate of them for a Task 1 or Task 2 answer, broken down per criterion with the sentences behind each one, so you have something concrete to feed into the arithmetic above.