Primer Melting Temperature (Tm) Calculator
Estimate the melting temperature of a DNA primer using the Wallace rule and the salt-adjusted GC formula.
How to use the Primer Melting Temperature
- Enter or select: Primer sequence, Na⁺ concentration.
- The results (Length, GC content, Tm (Wallace, 2·AT + 4·GC), Tm (salt-adjusted), Molecular weight) are calculated instantly as you type.
- Use “Copy link” to share the calculation with the same input values.
Formula
- Tm = 2(A+T) + 4(G+C) (for < 14 nt)
- Tm = 81.5 + 16.6·log₁₀[Na⁺] + 0.41·GC% − 600/N