Understanding i-Ready Diagnostic Scores & Percentiles

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children taking iready diagnostic test

i-Ready is an online learning platform for K-8 students that is used widely throughout schools in the United States. The i-Ready program allows parents and teacher to benchmark a child’s skill level in ready and math and provides personalized lessons depending on diagnostic scores.

If your child has recently taken an i-Ready Diagnostic test, you may be confused about what the score means and how to help your child improve. In this guide we break out typical i-Ready Diagnostic scores based on grade level (kindergarten through 8th grade) and time of year (fall, winter, and spring).

Click on your child’s grade below to see where students should be scoring depending on the time year. Remember – a score in the 50th percentile is considered “average”, so you can get a good idea of whether your student is behind or ahead of the curve and by how far.

Interested in helping your child improve in reading & math? Mastery Genius can help! For only $30 per month, we develop a personalized curriculum that pinpoints your child’s academic gaps and helps them master topics at their own pace – not the pace of an entire classroom.

i-Ready Diagnostic Scores & Percentiles by Grade

Click on your child’s grade below to get a better understanding of what their score means.

Kindergarten

Fall

Below are the diagnostic scores and corresponding percentiles for kindergarten students taken between the beginning of the school year and November 15th.

PercentileMathReading
1 – 9<=298 – 312<=286 – 307
10 – 19313 – 321309 – 321
20 – 29322 – 328322 – 329
30 – 39329 – 335330 – 335
40 – 49335 – 341336 – 341
50 – 59342 – 347341 – 347
60 – 69347 – 352348 – 356
70 – 79353 – 360357 – 366
80 – 89361 – 370367 – 382
90 – 99371 – 392+384 – 422+

Winter

Below are the diagnostic scores and corresponding percentiles for kindergarten students taken between the beginning November 16th and March 1st.

PercentileMathReading
1 – 9<=306 – 325<=296 – 325
10 – 19326 – 338328 – 341
20 – 29339 – 346342 – 352
30 – 39347 – 353353 – 361
40 – 49354 – 360362 – 370
50 – 59360 – 366371 – 380
60 – 69367 – 372381 – 392
70 – 79373 – 379393 – 403
80 – 89380 – 388404 – 413
90 – 99389 – 414+414 – 465+

Spring

Below are the diagnostic scores and corresponding percentiles for kindergarten students taken between the beginning March 2nd and the end of the school year.

PercentileMathReading
1 – 9<=313 – 339<=305 – 342
10 – 19341 – 354344 – 362
20 – 29355 – 363364 – 376
30 – 39364 – 371378 – 389
40 – 49371 – 377390 – 400
50 – 59378 – 383401 – 408
60 – 69384 – 388408 – 414
70 – 79389 – 395414 – 423
80 – 89396 – 405424 – 443
90 – 99406 – 435+447 – 504+

1st Grade

Fall

Below are the diagnostic scores and corresponding percentiles for 1st grade students taken between the beginning of the school year and November 15th.

PercentileMathReading
1 – 9<=312 – 338<=308 – 344
10 – 19340 – 352347 – 364
20 – 29353 – 362366 – 378
30 – 39363 – 370380 – 391
40 – 49370 – 375392 – 402
50 – 59376 – 381403 – 409
60 – 69382 – 388410 – 416
70 – 79388 – 393417 – 427
80 – 89393 – 402429 – 453
90 – 99404 – 431+456 – 508+

Winter

Below are the diagnostic scores and corresponding percentiles for 1st grade students taken between the beginning November 16th and March 1st.

PercentileMathReading
1 – 9<=323 – 356<=322 – 368
10 – 19358 – 371371 – 392
20 – 29372 – 380394 – 406
30 – 39381 – 387407 – 415
40 – 49388 – 392415 – 423
50 – 59393 – 398424 – 434
60 – 69399 – 405436 – 452
70 – 79406 – 413453 – 469
80 – 89413 – 425471 – 491
90 – 99426 – 449+494 – 535+

Spring

Below are the diagnostic scores and corresponding percentiles for 1st grade students taken between the beginning March 2nd and the end of the school year.

PercentileMathReading
1 – 9<=332 – 369<=332 – 386
10 – 19370 – 383390 – 410
20 – 29385 – 393411 – 422
30 – 39393 – 400423 – 436
40 – 49401 – 407438 – 453
50 – 59407 – 413454 – 467
60 – 69414 – 421468 – 480
70 – 79422 – 430482 – 495
80 – 89430 – 439497 – 516
90 – 99441 – 463+520 – 553+

2nd Grade

Fall

Below are the diagnostic scores and corresponding percentiles for 2nd grade students taken between the beginning of the school year and November 15th.

PercentileMathReading
1 – 9<=333 – 367<=339 – 389
10 – 19369 – 381393 – 411
20 – 29382 – 390413 – 424
30 – 39390 – 396425 – 443
40 – 49396 – 402443 – 459
50 – 59402 – 408460 – 473
60 – 69409 – 414475 – 487
70 – 79414 – 422489 – 503
80 – 89423 – 434505 – 522
90 – 99435 – 458+524 – 561+

Winter

Below are the diagnostic scores and corresponding percentiles for 2nd grade students taken between the beginning November 16th and March 1st.

PercentileMathReading
1 – 9<=348 – 381<=351 – 407
10 – 19383 0 395410 – 431
20 – 29396 – 404434 – 457
30 – 39405 – 411459 – 474
40 – 49412 – 417475 – 488
50 – 59418 – 424489 – 500
60 – 69425 – 432502 – 513
70 – 79433 – 441515 – 527
80 – 89443 – 449528 – 542
90 – 99450 – 471+544 – 579+

Spring

Below are the diagnostic scores and corresponding percentiles for 2nd grade students taken between the beginning March 2nd and the end of the school year.

PercentileMathReading
1 – 9<=355 – 391<=364 – 419
10 – 19393 – 406422 – 454
20 – 29407 – 416457 – 476
30 – 39416 – 424477 – 491
40 – 49425 – 433492 – 504
50 – 59434 – 441505 – 516
60 – 69442 – 447517 – 527
70 – 79447 – 454528 – 540
80 – 89455 – 462541 – 556
90 – 99463 – 484+558 – 592+

3rd Grade

Fall

Below are the diagnostic scores and corresponding percentiles for 3rd grade students taken between the beginning of the school year and November 15th.

PercentileMathReading
1 – 9<=354 – 387<=365 – 416
10 – 19390 – 403419 – 448
20 – 29404 – 412451 – 471
30 – 39413 – 420473 – 486
40 – 49420 – 427488 – 500
50 – 59428 – 434 502 – 515
60 – 69435 – 441516 – 527
70 – 79441 – 447528 – 540
80 – 89448 – 456541 – 556
90 – 99456 – 480+558 – 595+

Winter

Below are the diagnostic scores and corresponding percentiles for 3rd grade students taken between the beginning November 16th and March 1st.

PercentileMathReading
1 – 9<=365 – 402<=372 – 432
10 – 19404 – 419437 – 472
20 – 29420 – 429474 – 492
30 – 39430 – 437494 – 509
40 – 49437 – 444 512 – 521
50 – 59444 – 449522 – 532
60 – 69450 – 455534 – 544
70 – 79455 – 461545 – 557
80 – 89462 – 469558 – 573
90 – 99471 – 496+575 – 611+

Spring

Below are the diagnostic scores and corresponding percentiles for 3rd grade students taken between the beginning March 2nd and the end of the school year.

PercentileMathReading
1 – 9<=370 – 411<=378 – 446
10 – 19413 – 429452 – 484
20 – 29431 – 441486 – 505
30 – 39441 – 449507 – 520
40 – 49450 – 458522 – 533
50 – 59458 – 464534 – 545
60 – 69465 – 471546 – 557
70 – 79472 – 479558 – 570
80 – 89480 – 489571 – 586
90 – 99491 – 513+588 – 625+

4th Grade

Fall

Below are the diagnostic scores and corresponding percentiles for 4th grade students taken between the beginning of the school year and November 15th.

PercentileMathReading
1 – 9<=371 – 408<=382 – 447
10 – 19410 – 425453- 483
20 – 29426 – 436485 – 503
30 – 39437 – 444505 – 519
40 – 49445 – 451520 – 532
50 – 59452 – 459533 – 543
60 – 69460 – 466545 – 556
70 – 79466 – 473557 – 569
80 – 89474 – 482571 – 586
90 – 99484 – 508+588 – 627+

Winter

Below are the diagnostic scores and corresponding percentiles for 4th grade students taken between the beginning November 16th and March 1st.

PercentileMathReading
1 – 9<=380 – 419<=390 – 466
10 – 19421 – 438472 – 500
20 – 29439 – 448502 – 520
30 – 39449 – 458522 = 534
40 – 49459 – 565536 – 547
50 – 59465 – 470548 – 559
60 – 69471 – 477560 – 570
70 – 79478 – 485572 – 583
80 – 89486 – 495585 – 600
90 – 99496 – 518+603 – 638+

Spring

Below are the diagnostic scores and corresponding percentiles for 4th grade students taken between the beginning March 2nd and the end of the school year.

PercentileMathReading
1 – 9<=385 – 426<=393 – 473
10 – 19429 – 447478 – 509
20 – 29448 – 461512 – 528
30 – 39462 – 469530 – 543
40 – 49470 – 478545 – 557
50 – 59479 – 485558 – 569
60 – 69486 – 492570 – 581
70 – 79493 – 501582 – 593
80 – 89502 – 513595 – 612
90 – 99514 – 530+614 – 648+

5th Grade

Fall

Below are the diagnostic scores and corresponding percentiles for 5th grade students taken between the beginning of the school year and November 15th.

PercentileMathReading
1 – 9<=382 – 422<=401 – 475
10 – 19425 – 443479 – 509
20 – 29444 – 454513 – 529
30 – 39455 – 462530 – 543
40 – 49463 – 470545 – 556
50 – 59470 – 477558 – 568
60 – 69478 – 483569 – 581
70 – 79484 – 491582 – 594
80 – 89492 – 502596 – 614
90 – 99503 – 524+616 – 648+

Winter

Below are the diagnostic scores and corresponding percentiles for 5th grade students taken between the beginning November 16th and March 1st.

PercentileMathReading
1 – 9<=392 – 434<=405 – 488
10 – 19437 – 452493 – 522
20 – 29453 – 464524 – 541
30 – 39465 – 472543 – 556
40 – 49473 – 480558 – 568
50 – 59480 – 487570 – 580
60 – 69487 – 494582 – 592
70 – 79494 – 501593 – 607
80 – 89502 – 512609 – 623
90 – 99512 – 535+625 – 661+

Spring

Below are the diagnostic scores and corresponding percentiles for 5th grade students taken between the beginning March 2nd and the end of the school year.

PercentileMathReading
1 – 9<=396 – 439<=408 – 494
10 – 19442 – 460499 – 530
20 – 29461 – 471531 – 550
30 – 39472 – 481551 – 564
40 – 49482 – 490566 – 577
50 – 59490 – 496579 – 589
60 – 69497 – 505591 – 604
70 – 79505 – 513605 – 618
80 – 89514 – 524619 – 633
90 – 99525 – 544+635 – 671+

6th Grade

Fall

Below are the diagnostic scores and corresponding percentiles for 6th grade students taken between the beginning of the school year and November 15th.

PercentileMathReading
1 – 9<=391 – 431<=410 – 486
10 – 19434 – 451491 – 522
20 – 29452 – 463524 – 542
30 – 39464 – 473544 – 558
40 – 49474 – 482560 – 571
50 – 59483 – 489573 – 584
60 – 69490 – 496586 – 598
70 – 79497 – 504600 – 614
80 – 89505 – 514615 – 630
90 – 99515 – 540632 – 669+

Winter

Below are the diagnostic scores and corresponding percentiles for 6th grade students taken between the beginning November 16th and March 1st.

PercentileMathReading
1 – 9<=396 – 440<=412 – 495
10 – 19442 – 459500 – 531
20 – 29460 – 471534 – 552
30 – 39472 – 481554 – 567
40 – 49482 – 489569 – 581
50 – 59490 – 496582 – 593
60 – 69497 – 504595 – 608
70 – 79505 – 513610 – 622
80 – 89513 – 524623 – 638
90 – 99526 – 550+640 – 679+

Spring

Below are the diagnostic scores and corresponding percentiles for 6th grade students taken between the beginning March 2nd and the end of the school year.

PercentileMathReading
1 – 9<=399 – 442<=413 – 500
10 – 19444 – 464505 – 537
20 – 29466 – 477540 – 559
30 – 39479 – 488561 – 575
40 – 49489 – 496576 – 588
50 – 59497 – 504590 – 603
60 – 69505 – 513604 – 617
70 – 79513 – 522618 – 630
80 – 89523 – 537631 – 646
90 – 99538 – 559+648 – 682+

7th Grade

Fall

Below are the diagnostic scores and corresponding percentiles for 7th grade students taken between the beginning of the school year and November 15th.

PercentileMathReading
1 – 9<=401 – 441<=418 – 501
10 – 19444 – 462508 – 538
20 – 29463 – 475540 – 559
30 – 39476 – 486560 – 574
40 – 49486 – 493576 – 589
50 – 59493 – 500590 – 604
60 – 69501 – 507605 – 618
70 – 79508 – 514619 – 630
80 – 89516 – 529632 – 645
90 – 99530 – 558+648 – 687+

Winter

Below are the diagnostic scores and corresponding percentiles for 7th grade students taken between the beginning November 16th and March 1st.

PercentileMathReading
1 – 9<=402 – 444<=423 – 514
10 – 19447 – 467518 – 548
20 – 29468 – 480551 – 569
30 – 39482 – 490571 – 585
40 – 49491 – 498587 – 600
50 – 59499 – 506602 – 614
60 – 69506 – 513616 – 627
70 – 79514 – 524628 – 637
80 – 89525 – 538639 – 655
90 – 99540 – 566+657 – 695+

Spring

Below are the diagnostic scores and corresponding percentiles for 7th grade students taken between the beginning March 2nd and the end of the school year.

PercentileMathReading
1 – 9<=403 – 448<=424 – 516
10 – 19451 – 471522 – 551
20 – 29473 – 486554 – 575
30 – 39487 – 495577 – 591
40 – 49496 – 503593 – 608
50 – 59504 – 513609 – 621
60 – 69513 – 521622 – 632
70 – 79522 – 532633 – 644
80 – 89533 – 548645 – 660
90 – 99550 – 575+662 – 695+

8th Grade

Fall

Below are the diagnostic scores and corresponding percentiles for 8th grade students taken between the beginning of the school year and November 15th.

PercentileMathReading
1 – 9<=406 – 447<=431 – 518
10 – 19450 – 469523 – 550
20 – 29471 – 483555 – 573
30 – 39484 – 492575 – 589
40 – 49493 – 500591 – 605
50 – 59501 – 509607 – 619
60 – 69510 – 517620 – 631
70 – 79518 – 527632 – 641
80 – 89529 – 543642 – 660
90 – 99545 – 572+663 – 696+

Winter

Below are the diagnostic scores and corresponding percentiles for 8th grade students taken between the beginning November 16th and March 1st.

PercentileMathReading
1 – 9<=406 – 451<=434 – 525
10 – 19454 – 474531 – 562
20 – 29476 – 488564 – 583
30 – 39489 – 496584 – 600
40 – 49497 – 505601 – 615
50 – 59506 – 515616 – 626
60 – 69515 – 524627 – 636
70 – 79525 – 536637 – 648
80 – 89537 – 551650 – 666
90 – 99552 – 579+669 – 704+

Spring

Below are the diagnostic scores and corresponding percentiles for 8th grade students taken between the beginning March 2nd and the end of the school year.

PercentileMathReading
1 – 9<407 – 453<=434 – 529
10 – 19457 – 478535 – 567
20 – 29480 – 491569 – 589
30 – 39492 – 500590 – 607
40 – 49501 – 511609 – 621
50 – 59512 – 521622 – 632
60 – 69522 – 531633 – 642
70 – 79532 – 542643 – 654
80 – 89544 – 556655 – 669
90 – 99558 – 585+671 – 704+

Conclusion

We hope this guide has helped you get a better idea of what your child’s i-Ready Diagnostic score means and where they fall in the percentile range. For more detailed data, please check out the official i-Ready Diagnostic National Norms Tables for Reading and Mathematics resource.