A feedback bundle costs what you pay divided by the corrections you use. Unused credits, expiry dates and mandatory fees can make the effective price much higher than the advertised price per task.
This guide provides a calculation method. The examples are hypothetical, not merchant prices. Current published offers appear in our IELTS service comparison and OET service comparison.
Start with a comparable unit
Decide what you are buying: one essay, one letter, two examination tasks, one live session, or a correction followed by a revised submission. Until that is clear, “per test” and “per correction” can describe different products.
Then record the base price, mandatory fees, currency code, included credits, usable access period and any charges for the follow-up you need. Do not add optional extras that you would not buy merely to make a competitor appear expensive.
Two calculations answer different questions
Nominal cost per credit = total payable amount ÷ included credits.
Effective cost per used cycle = total payable amount ÷ cycles you will realistically complete.
The second denominator must not exceed the credits you can actually use. A cycle is your planning unit: submit, understand, revise and apply. It is not a universal definition imposed on every seller.
| Illustrative offer | Total price | Included credits | Credits used | Nominal cost | Effective used cost |
|---|---|---|---|---|---|
| A | 60 units | 10 | 3 | 6 | 20 |
| B | 36 units | 4 | 3 | 9 | 12 |
| C | 15 units | 1 | 1 | 15 | 15 |
Assume the same currency and comparable deliverables solely for this illustration. B has a higher headline per-credit cost than A, but a lower total commitment and lower cost per used credit for this buyer. That does not establish that B's feedback is better.
Revisions can change the denominator
Suppose four credits are advertised. When every revised submission consumes another credit, those credits might cover two attempt-and-revision pairs rather than four pairs. When clarification is included without consuming a credit, a different structure applies.
Write down the process instead of arguing over the word “correction.” What will you submit, what will you receive, and what happens next? The process makes products comparable.
Convert currency carefully—or do not convert it
A dollar symbol can refer to different currencies. Label it “currency code unconfirmed” when the source does not resolve that. Do not silently treat all dollar prices as US dollars.
When converting, record the original amount, the rate and date, and payment or foreign-exchange fees where known. A public exchange-rate calculation is not necessarily the amount charged by your card issuer. Leaving original-currency prices side by side is more honest than a falsely precise cheapest-provider ranking.
Deadlines are part of usability
A provider returning feedback before your examination is not enough when you have no time left to understand and practise it. Work backwards from the date by allowing submission time, the stated response window, revision and a fresh attempt.
A rushed pack of corrections may generate documents but no usable practice. Conversely, buying long access for a short, defined need can commit unnecessary money.
Use the local calculator
The package includes a feedback value calculator. It runs in the browser, uses figures you enter and does not claim to compare learning outcomes. It does not contain live merchant prices, exchange rates or a pass-probability model.
Keep a free resource as the baseline. Pay for the missing output—individual diagnosis, clear explanation, clarification or structured teaching—not merely for an attractive discount percentage.