Your refractometer reads Brix — not concentration. Brix is a sugar-water scale; coolant isn’t sugar water. To get your real concentration you multiply the Brix reading by your coolant’s correction factor. Skip that step and you can be off by half. Here’s the math, done for you.
⚠️ Always confirm your coolant’s correction factor with your coolant distributor (or its current product data sheet) before mixing. Factors are specific to each exact product grade and can change when a coolant is reformulated.
Pick your coolant (or enter a factor) and a Brix reading to begin.
How do I find my coolant’s correction factor?
It’s specific to each product. In order of ease:
Your coolant’s Technical Data Sheet (TDS) — look for “refractometer factor,” “RI,” or “refractive index.”
The product label or the manufacturer’s website.
Ask your coolant distributor for “the refractometer factor for [product].”
No one can tell you? Build your own: mix a carefully measured known batch — e.g. exactly 5% (5 parts concentrate to 95 parts of your shop’s mix water). Read the Brix. Then factor = known % ÷ Brix reading. (A true 5% reading 2.5 Brix → factor 5 ÷ 2.5 = 2.0.)
The right way to read a refractometer
Zero it with the same water you mix coolant with (not just any water) — adjust until the line sits on 0.
Clean prism, room-temperature sample; let it settle so the boundary line is sharp.
Read where the light/dark line crosses the scale, then multiply by your factor.
Get the printable correction-factor chart (48 coolants)
Every factor independently verified June 2026 — for the wall by your refractometer.
✓ Your correction-factor chart
Independently verified June 2026 against each maker’s own data sheet. Always confirm your exact product grade with your coolant distributor (or its current data sheet) before mixing — factors are per-product and change with reformulation.
Coolant (verify exact grade)
Factor
From the manufacturer’s data sheet
Master Fluid Solutions (TRIM)
TRIM SOL
1.0
TRIM E206
1.0
TRIM MicroSol 685XT
1.1
TRIM MicroSol 585XT
1.2
TRIM MicroSol 690XT
1.2
TRIM SC520
1.8
TRIM HyperSol 888NXT
2.2
TRIM C270
3.3
Quaker Houghton
HOCUT 795
1.0
HOCUT 795 MP
1.5
QUAKERCOOL 3100
1.6
QUAKERCOOL 3610 HBFF
1.92
HOCUT 768
2.4
Cimcool
CIMPERIAL 1070
1.0
CIMPERIAL 1070-HFP
1.0
Cimstar 60C
1.6
Cimtech 310
1.7
Cimtech 95 / 100
4.2
Castrol
Cooledge CB
0.95
Syntilo R Plus
1.0
Hysol MB 50
1.0
Hysol SL 35 XBB
1.1
Alusol B
1.0
Hysol 6519
1.4
Syntilo 9913
1.4
Hysol SL 20 XBB
1.6
Alusol 32 BF
1.6
Syntilo 9930
2.3
Fuchs
Ecocool S 761 B
1.0
QualiChem
XTREME CUT 250C
1.0
Q-COOL 330C
3.0
Manufacturer data, distributor-hosted — confirm with your distributor
Blaser Swisslube
Blasocut 2000 CF
1.0
Blasocut 2000 Universal
1.0
Blasocut BC 25 MD
1.0
Blasocut BC 935 SW
1.0
Blasocut 4000 Strong
1.0
B-Cool MC 610
1.4
Vasco 7000
1.4
Synergy 735
1.4
B-Cool 9665
1.8
Chemetall Tech Cool
Tech Cool 35075
1.0
Tech Cool 35048
1.1
Tech Cool 35058
1.1
Tech Cool 35052CF
1.13
Tech Cool 35037
1.25
Tech Cool 35200
1.67
Tech Cool 35035NB
1.96
Tech Cool 35100NB
2.17
Tired of chasing concentration? A refractometer tells you it’s drifting — a coolant proportioner/mixer stops it drifting by mixing every gallon of make-up correctly. Zebra builds both. Shop refractometers →Shop coolant mixers →
The formula: Actual concentration % = Brix reading × correction factor. Correction amounts use the standard mass-balance: to raise a V-gal sump from c% to target T%, add V×(T−c)÷(100−T) gal concentrate; to lower it, add V×(c−T)÷T gal water. Treat correction amounts as close estimates — re-check after adjusting. 48 factors independently verified June 2026; always confirm your exact grade with your coolant distributor before mixing.
