Beta Williamson County, TX only — data and coverage are limited during early access.

3912 SAPPHIRE LOOP, ROUND ROCK, TX 78681

ROUND ROCK, 78681 — williamson County

3 bed2 bath2,521 sqftBuilt 2008

Property at a Glance

This home is estimated between $458,438 and $729,713, with a best estimate of $494,879. That places the property below the L495414C - BORHO/MAYFIELD RANCH/SAPPHIRE LOOP median of $623,673, in a neighborhood that declined 8.0% over the past year.

Estimated Value Range

$458,438 $729,713
Best Estimate
$494,879
WCAD Value
$603,157
High Confidence

Based on 5 comparable properties(5 in the same subdivision)

Based on 5 comparable properties in L495414C - BORHO/MAYFIELD RANCH/SAPPHIRE LOOP, this home's estimated market value is between $458,438 and $729,713. All 5 comparables are in the same subdivision, giving this estimate high confidence.

Comparable Properties (5)

3917 SAPPHIRE LOOP, ROUND ROCK, TX 78681
0.00 mi 100% similar Same subdivision
4 bed 3 bath 2,205 sqft Built 2011
Raw Value $638,861
Adjusted Value $729,713

Adjusted +$96,844 for 316 sqft more living space and -$5,992 for being older. Net adjustment: +$90,852.

3929 SAPPHIRE LOOP, ROUND ROCK, TX 78681
0.00 mi 100% similar Same subdivision
3 bed 2 bath 2,517 sqft Built 2007
Raw Value $491,656
Adjusted Value $494,879

Adjusted +$1,226 for 4 sqft more living space and +$1,997 for being newer. Net adjustment: +$3,223.

3920 SAPPHIRE LOOP, ROUND ROCK, TX 78681
0.00 mi 100% similar Same subdivision
4 bed 3 bath 2,496 sqft Built 2011
Raw Value $498,039
Adjusted Value $499,709

Adjusted +$7,662 for 25 sqft more living space and -$5,992 for being older. Net adjustment: +$1,670.

3815 SAPPHIRE LOOP, ROUND ROCK, TX 78681
0.00 mi 100% similar Same subdivision
3 bed 2 bath 2,861 sqft Built 2008
Raw Value $562,637
Adjusted Value $458,438

Adjusted -$104,199 for 340 sqft less living space. Net adjustment: -$104,199.

4100 SAPPHIRE LOOP, ROUND ROCK, TX 78681
0.00 mi 100% similar Same subdivision
3 bed 2 bath 2,852 sqft Built 2007
Raw Value $559,535
Adjusted Value $460,091

Adjusted -$101,441 for 331 sqft less living space and +$1,997 for being newer. Net adjustment: -$99,444.

The Neighborhood

This home is valued 3.3% below the L495414C - BORHO/MAYFIELD RANCH/SAPPHIRE LOOP median of $623,673. That positions it competitively for buyers comparing within the neighborhood. Note that values in this subdivision declined 8.0% over the past year.

L495414C - BORHO/MAYFIELD RANCH/SAPPHIRE LOOP

typical
427 Properties
$623,673 Median Value
-8.0% YoY Change
1% Have Pool
100% Have Garage
This Home
$603,157
Median
$623,673

This home is -3.3% below the subdivision median.

Tax Analysis

The estimated annual property tax is $12,021 across all districts. With a homestead exemption claimed, that drops to $10,388 — saving $1,633 per year. That's $866 per month a buyer should budget. The assessed value increased roughly in line with the neighborhood, so a tax protest is unlikely to yield significant savings.

Tax Districts

DistrictTypeRateAnnual Amount
Leander ISDSchool1.0869%$6,556
Round RockCity0.3720%$2,244
Williamson CountyCounty0.3694%$2,228
Austin Community Collegespecial0.1034%$624
Williamson County FM/RdCounty0.0443%$267
Upper Brushy Creek WCIDWater0.0170%$103
Williamson Central Appraisal Districtcad0.0000%$0
Total Annual Tax1.9931%$12,021

Mortgage Context

At today's 30-year mortgage rate of 6.38%, a buyer financing $494,879 would pay approximately $3,089 per month (principal and interest only, excluding taxes and insurance).

Data sourced from Williamson County Appraisal District (WCAD), Texas Education Agency (TEA), and Federal Reserve Economic Data (FRED). Assessment values reflect the appraisal district's estimate, not market sale prices. Report generated 4/18/2026.

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