Looking to answer another question on this site, to did some math and fired up LTspice to check some values and I am not able to the -3dB point.
I found the transfer function to be
$$ H(s) = \cfrac{1 + \cfrac{s}{\cfrac{1}{R_2C_1}}}{1+ \cfrac{s}{\frac{1}{(R_1+ R_2)C_1}}} $$ This equation was corrected based off the answer that @ThePhoton had pointed out.
Where the \$w_z = \frac{1}{R_2 C_1} = 10,000 \$ and \$ f_z = \frac{w_z}{2 \pi} = 1.592\$ kHz
The same is done for the pole
\$ w_p = 2000\$ and \$ f_p = 318.3 \$ Hz
On the plot above, I am measuring the output at R2, I have placed cursors as closely as I can get it to the \$f_p \$ and \$ f_z \$ and if we look at the magnitude I am getting -2.83 dB and -11.14 dB respectively.
It's like I am off by ~ 0.2 dB for both, because I am expected -3dB and -13.97dB.
I must be missing something. What is it ?
edit Adding my .asc file if anyone wants to try
Version 4
SHEET 1 880 680
WIRE 128 64 48 64
WIRE 336 64 208 64
WIRE 336 80 336 64
WIRE 48 128 48 64
WIRE 336 208 336 160
FLAG 336 272 0
FLAG 48 208 0
SYMBOL voltage 48 112 R0
WINDOW 123 24 124 Left 2
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 1
SYMATTR Value2 AC 1
SYMBOL res 224 48 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R1
SYMATTR Value 400
SYMBOL res 352 176 R180
WINDOW 0 36 76 Left 2
WINDOW 3 36 40 Left 2
SYMATTR InstName R2
SYMATTR Value 100
SYMBOL cap 320 208 R0
SYMATTR InstName C1
SYMATTR Value 1µ
TEXT 14 296 Left 2 !.ac oct 10000 1 10000