For SLPs, school psychologists & IEP teams
Retest Date Calculator
When can you give the test again?
The date, the countdown and the age.
Many tests need a minimum gap before they are given again. Enter the date of the last test and the wait period, and get the earliest retest date, how many days are left, and the child’s age on that day.
- 3 months to 3 years
- Days and weeks left
- Age on the retest date
- Re-evaluation planning
When can you test again?
Enter the date of the last test and choose the interval.
- Earliest retest date
- Interval
- Age on retest date
Show calculation steps
Three steps
How to use the retest date calculator
One date and one interval. The date of birth is optional.
- Enter the date of the last test.
- Choose how long to wait. Check the test manual for its minimum retest interval. For re-evaluations, choose 3 years.
- Add the date of birth (optional) to see the child’s age on the retest date, then press Find retest date.
Worked example
A one-year retest
A student born on September 28, 2016 was tested on March 10, 2026. The test should not be repeated for 12 months.
The retest date
March 10, 2026 + 12 months = March 10, 2027.
The calculator also counts how many days and weeks are left from today.
Age on that day
On March 10, 2027 the student will be 10 years, 5 months and 10 days old (10;5.10).
Use that age to pick the right norms for the new test.
Why the wait
Why is there a waiting period?
Giving a test again too soon can make the scores less accurate.
- Practice effects: someone who saw the items recently may score higher just because they remember them.
- Test manuals: many standardized tests state a minimum time between administrations. Always check yours.
- Re-evaluations: in the US, students with an IEP are re-evaluated at least once every 3 years, and usually not more than once a year unless the parent and school agree.
- Progress monitoring: short probes and screeners are designed to be repeated often, so they usually don’t need a long gap.
Still unsure?
Questions people ask
Tap a question to open it.
How long should I wait before giving a test again?
It depends on the test. Many standardized tests recommend waiting 6 to 12 months, and some longer. The manual for your test is the authority, so check its section on retesting.
What if the last test was on the 31st?
When the target month is shorter, the date moves to the last day of that month. For example, 6 months after August 31 is February 28 (or 29 in a leap year).
What does “you can retest now” mean?
The waiting period has already passed, so the earliest retest date is in the past.
Why add the date of birth?
So the calculator can show the child’s age on the retest date, which you’ll need to choose the right norms.
Is any information saved?
No. Everything is calculated in your browser and nothing is sent or stored.