RAM True Latency Calculator
CAS Latency (CL) alone doesn't tell you real-world speed — it has to be read alongside the data rate. This calculator converts both into the actual first-word access time in nanoseconds, using the standard JEDEC memory timing formula.
RAM True Latency Calculator
Enter your own kit's CAS Latency and data rate (from the spec sheet or box) — this uses the standard JEDEC timing formula, not a claim about any specific product.
12.00 ns
true first-word latency
Formula: (CL ÷ (data rate ÷ 2)) × 1000. Lower ns generally means faster real-world response — a higher CL number at a higher data rate can still land at a similar or better ns value than a lower CL at a lower data rate.
See real DDR5 kits with honest buying criteria.
Read the RAM Buying GuideWhy CL numbers alone are misleading
A CL36 kit at DDR5-6000 and a CL30 kit at DDR5-5000 both work out to the same 12ns true latency — the CL number by itself, without the data rate, doesn't tell you which kit actually responds faster. Full buying criteria in our RAM buying guide.
Frequently Asked Questions
What formula does this calculator use?
The standard JEDEC memory timing formula: true latency (ns) = (CAS Latency ÷ (data rate MT/s ÷ 2)) × 1000. This is the same math used industry-wide to compare memory kits fairly.
Why do two kits with different CL numbers have the same true latency?
Because CL is only meaningful alongside the data rate — a higher-speed kit can use a higher CL number and still land at the same, or better, true nanosecond latency than a slower kit with a lower CL.