Stanford-Binet 5 (SB5) Scores Explained: Ranges and Factors

The Stanford-Binet Intelligence Scales, Fifth Edition (SB5) reports a Full Scale IQ on the same mean-100, standard-deviation-15 scale as the Wechsler tests, built from five factors rather than Wechsler's index structure. Riverside Insights, its publisher, uses it across the widest span of any test covered on this site: age 2 through 85 and older, in one continuous battery. A sixth edition is already in norming as this is written, which changes what "current" means for anyone comparing a score against the published norms.

What is the Stanford-Binet 5 and who takes it?

The Stanford-Binet line is the oldest in intelligence testing: Alfred Binet and Theodore Simon published the first version in 1905, and Lewis Terman's Stanford revision of 1916 gave the scale its name. The fifth edition, published in 2003 and written by Gale Roid, covers ages 2 years to 85 years and older in a single battery, according to Riverside's authorized distributor WPS. That is wider than any single Wechsler scale: the WAIS-5 covers ages 16 to 90, the WISC-V ages 6 to 16, and the WPPSI-IV only 2:6 to 7:7 (see our guides to WAIS-IV and WAIS-5 and WPPSI-IV scores), which is one reason the SB5 stays in wide use for testing very young children and adults on the same instrument. For a broader introduction to the test's history, our blog's Stanford-Binet IQ test overview covers the earlier editions this one replaced.

What do the five SB5 factors measure?

SB5 organizes its items into five factors and splits each one into a nonverbal and a verbal subtest, for ten subtests in total. Riverside's own materials describe it as the first Binet edition to measure all five factors in both a verbal and a nonverbal form.

• Fluid Reasoning
• Knowledge
• Quantitative Reasoning
• Visual-Spatial Processing
• Working Memory

Two of the ten subtests carry extra weight: Nonverbal Fluid Reasoning is tested with Object Series/Matrices, and Verbal Knowledge with a Vocabulary subtest, and those two alone are what the short form of the test uses (below). SB5's technical manual is sold rather than posted online, so this article names only the two routing subtests with confidence and describes the rest at the factor level rather than guessing at titles it cannot check.

What are the SB5 composite scores?

SB5 reports four IQ-type composites plus the five factor indexes. The Full Scale IQ (FSIQ) uses all ten subtests. The Abbreviated Battery IQ (ABIQ) uses only two — Object Series/Matrices and Vocabulary — as a short screening composite. A Verbal IQ (VIQ) totals the five verbal subtests and a Nonverbal IQ (NVIQ) the five nonverbal ones. Every composite, including the five factor indexes, sits on the familiar mean-100, standard-deviation-15 scale; the ten individual subtests use a smaller scaled-score metric with a mean of 10 and a standard deviation of 3, the same convention the Wechsler scales use, according to Wiley's published excerpt from Essentials of SB5 Assessment.

Because the ABIQ comes from only two subtests, chosen for their ability to predict scores on the full battery, it is a screening estimate and not a substitute for the Full Scale IQ — the same caution our guide to full-scale IQ against index scores gives for any composite built from fewer subtests than the total.

What do SB5 scores mean?

SB5 scores read the same way as any test on this mean-100, SD-15 scale: 100 is average, about two-thirds of people score between 85 and 115, and a 130 is the 97.7th percentile, one person in 44. Riverside's examiner materials attach a descriptive label to each band. The two ends of the table are directly confirmed — 145 to 160 as "Very gifted or highly advanced" and 40 to 54 as "Moderately impaired or delayed" — and the ranges below are the ones commonly published alongside the test; treat the middle boundaries as the widely cited convention rather than a figure pulled from the technical manual itself, which is sold rather than posted online.

• 145 to 160: Very gifted or highly advanced
• 130 to 144: Gifted or very advanced
• 120 to 129: Superior
• 110 to 119: High average
• 90 to 109: Average
• 80 to 89: Low average
• 70 to 79: Borderline impaired or delayed
• 55 to 69: Mildly impaired or delayed
• 40 to 54: Moderately impaired or delayed

Our percentile calculator converts any score on this scale to a percentile directly, and our guide to the Mensa IQ score requirement works through the same arithmetic for a specific, widely quoted cutoff.

What else is the SB5 used for?

Beyond general cognitive assessment, Texas's state autism resource center lists the SB5 among the instruments used in autism spectrum evaluations, and testing specialists commonly favor it for giftedness identification in very young children precisely because of its wide age range and high item ceiling — a child does not run out of room at the top of the scale as quickly as on a test built for a narrower age band.

What SB5 score counts as gifted?

Riverside publishes no single gifted cutoff for the SB5; like the WPPSI-IV and WISC-V, that decision is left to the school or program using the score (see our guide to universal screening for gifted programs). Individual districts publish their own thresholds. Scottsdale Unified School District's Comprehensive Gifted Program, for example, accepts either the SB5 or the WISC-V and requires a Full Scale IQ of 130 or above for kindergarten eligibility and 135 or above for grades 1 through 8 — a concrete illustration of a working cutoff set above the test's own "gifted" label, which starts at 130 on the SB5 scale itself.

How does the SB5 compare with the Wechsler scales?

The two test families share a scale but are not interchangeable instruments. One published comparison in adolescents on the autism spectrum (ages 10 to 16, n=40) found SB5 and WISC-IV Full Scale IQ scores correlated at r=0.78 to 0.88 but did not always agree on the exact score for the same child (Autism, 2015). That is a reason to treat a single score from either test as an estimate with a margin of error rather than an exact number — our guide to IQ score margin of error explains why, and our WISC-V index scores guide covers the current Wechsler equivalent for school-age children.

Is a sixth edition coming?

Yes, and it matters for anyone comparing a current score against the published norms. ProEd's own field-examiner norming portal currently lists an active Stanford-Binet Sixth Edition standardization study, expanding the age range to 3 through 90, as of the time this article was written. Riverside's own retail listing for the test still shows only the SB5, with no SB6 product yet, so the fifth edition — standardized on a sample of roughly 4,800 people stratified against 2001 US Census figures — remains the current, purchasable version. Our piece on the Flynn effect and expiring norms explains why the age of a norm sample matters: a 2003 sample compares today's test-taker with children and adults tested more than two decades ago.

An SB5 score is a range on the familiar mean-100, SD-15 scale, best read as five factor scores rather than one number — and, like any test, only as current as its norm sample. The IQ Metrics test reports a score on the same scale with its percentile shown alongside it.

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