Annealing Temperature Calculator

Calculate optimal PCR primer annealing temperature based on melting temperature (Tm) calculations.

Primer Sequences

Tm Formulas

Basic: Tm = 2(A+T) + 4(G+C)

Salt: Tm = 81.5 + 16.6×log[Na+] + 0.41(%GC) - 675/N

Optimal Annealing Temperature

46.8°C
Range: 43.8°C - 49.8°C

Forward Primer

Melting Temperature (Tm)54.4°C
Length21 bp
GC Content52.4%
CompositionA:5 T:5 G:6 C:5

Reverse Primer

Melting Temperature (Tm)51.8°C
Length20 bp
GC Content50.0%
CompositionA:5 T:5 G:5 C:5