How accurate are practice SAT scores?

The honest answer is that it depends almost entirely on how you took the test, and only secondarily on which platform you used.

The three sources of error#Link to the section: The three sources of error

**Conversion error.** Turning a raw count into a scaled score requires the College Board's equating data, which is not public. Every third-party platform calibrates its own table, and every such table has error in it. This is the part the platform owns, and it is the part that should be disclosed rather than hidden behind a confident-looking number.

**Your own variance.** You do not have one true score. You have a distribution. The same person, on the same material, on two different days, produces different results — and the spread is wider than most people expect. This is why a single mock is weak evidence and three are much stronger.

**Conditions.** This is the largest source of error and the only one entirely under your control. A mock taken in pieces, with the phone nearby, pausing between modules, is not measuring what a real sitting measures. It is measuring your knowledge, which you already knew you had, without the constraint that actually costs people points.

What makes a practice score informative#Link to the section: What makes a practice score informative

Sit it in one go. Both sections, one 10-minute break, nothing else. If you cannot do that today, do not take the mock today — an interrupted mock produces a number you will then have to distrust.

No notes, no lookups, no restarting a module. The moment you check something mid-test the score stops being comparable to a real one.

Real timing. 32 minutes per Reading and Writing module, 35 per Math module. Not "roughly". The pacing is what most people are actually failing at.

Morning, if your test is in the morning. Which it will be.

An honest mock is uncomfortable, and that discomfort is the measurement. A score you inflated tells you nothing except that you can inflate a score.

What it can and cannot predict#Link to the section: What it can and cannot predict

It can tell you your current ability level within a band. That is genuinely useful: it answers "is my target realistic from here" and "which section needs the work", which are the two decisions that matter while you still have time to act.

It cannot tell you what you will score on one specific Saturday. Test-day variance is real and no practice platform observes it. Treat a practice band as a description of where you are, not a prediction of where you will land.

It is also worth knowing which direction the errors usually run. Practice scores tend to come in **high** relative to a real sitting, for reasons that are behavioural rather than statistical: practice conditions are gentler, there is no consequence, and people unconsciously give themselves latitude they will not have on the day. If your practice scores are consistently above where real sittings land, the conditions are the first thing to examine.

Making your own scores more useful#Link to the section: Making your own scores more useful

Sit at least three, spaced out, all under the same conditions. Consistency across mocks matters more than the count.

Take one early. A mock in week one feels bad and saves weeks, because it tells you where to spend the time you have instead of where you assumed it should go.

Track the centre of your band moving, not the width. The width narrows on a schedule as evidence accumulates — ±60 after one, ±45 after two, ±40 after three or more here. That narrowing is not improvement. The centre moving is.

And do not retake a mock you have already seen. Remembered questions inflate the score and destroy the measurement, which was the only thing the mock was for.