Z Table - Z Score Table

Negative Z Table

This Negative Z Table can help you to find the values that are left of the mean. Table entries for z define the area under the standard normal curve to the left of the Z. Lastly, the negative score represents the corresponding values that are less than the mean.

Z00.010.020.030.040.050.060.070.080.09
-3.90.000050.000050.000040.000040.000040.000040.000040.000040.000030.00003
-3.80.000070.000070.000070.000060.000060.000060.000060.000050.000050.00005
-3.70.000110.00010.00010.00010.000090.000090.000080.000080.000080.00008
-3.60.000160.000150.000150.000140.000140.000130.000130.000120.000120.00011
-3.50.000230.000220.000220.000210.00020.000190.000190.000180.000170.00017
-3.40.000340.000320.000310.00030.000290.000280.000270.000260.000250.00024
-3.30.000480.000470.000450.000430.000420.00040.000390.000380.000360.00035
-3.20.000690.000660.000640.000620.00060.000580.000560.000540.000520.0005
-3.10.000970.000940.00090.000870.000840.000820.000790.000760.000740.00071
-30.001350.001310.001260.001220.001180.001140.001110.001070.001040.001
-2.90.001870.001810.001750.001690.001640.001590.001540.001490.001440.00139
-2.80.002560.002480.00240.002330.002260.002190.002120.002050.001990.00193
-2.70.003470.003360.003260.003170.003070.002980.002890.00280.002720.00264
-2.60.004660.004530.00440.004270.004150.004020.003910.003790.003680.00357
-2.50.006210.006040.005870.00570.005540.005390.005230.005080.004940.0048
-2.40.00820.007980.007760.007550.007340.007140.006950.006760.006570.00639
-2.30.010720.010440.010170.00990.009640.009390.009140.008890.008660.00842
-2.20.01390.013550.013210.012870.012550.012220.011910.01160.01130.01101
-2.10.017860.017430.0170.016590.016180.015780.015390.0150.014630.01426
-20.022750.022220.021690.021180.020680.020180.01970.019230.018760.01831
-1.90.028720.028070.027430.02680.026190.025590.0250.024420.023850.0233
-1.80.035930.035150.034380.033620.032880.032160.031440.030740.030050.02938
-1.70.044570.043630.042720.041820.040930.040060.03920.038360.037540.03673
-1.60.05480.05370.052620.051550.05050.049470.048460.047460.046480.04551
-1.50.066810.065520.064260.063010.061780.060570.059380.058210.057050.05592
-1.40.080760.079270.07780.076360.074930.073530.072150.070780.069440.06811
-1.30.09680.09510.093420.091760.090120.088510.086910.085340.083790.08226
-1.20.115070.113140.111230.109350.107490.105650.103830.102040.100270.09853
-1.10.135670.13350.131360.129240.127140.125070.123020.1210.1190.11702
-10.158660.156250.153860.151510.149170.146860.144570.142310.140070.13786
-0.90.184060.181410.178790.176190.173610.171060.168530.166020.163540.16109
-0.80.211860.208970.206110.203270.200450.197660.194890.192150.189430.18673
-0.70.241960.238850.235760.23270.229650.226630.223630.220650.21770.21476
-0.60.274250.270930.267630.264350.261090.257850.254630.251430.248250.2451
-0.50.308540.305030.301530.298060.29460.291160.287740.284340.280960.2776
-0.40.344580.34090.337240.33360.329970.326360.322760.319180.315610.31207
-0.30.382090.378280.374480.37070.366930.363170.359420.355690.351970.34827
-0.20.420740.416830.412940.409050.405170.401290.397430.393580.389740.38591
-0.10.460170.45620.452240.448280.444330.440380.436440.432510.428580.42465
00.50.496010.492020.488030.484050.480060.476080.47210.468120.46414
Positive Z Score Table

You can use this Positive Z Score Table to find the values that are right of the mean. Table entries for z define the area under the standard normal curve to the left of the Z. Positive score in Z-Table represents the corresponding values that are greater than the mean.

Z00.010.020.030.040.050.060.070.080.09
00.50.503990.507980.511970.515950.519940.523920.52790.531880.53586
0.10.539830.54380.547760.551720.555670.559620.563560.567490.571420.57535
0.20.579260.583170.587060.590950.594830.598710.602570.606420.610260.61409
0.30.617910.621720.625520.62930.633070.636830.640580.644310.648030.65173
0.40.655420.65910.662760.66640.670030.673640.677240.680820.684390.68793
0.50.691460.694970.698470.701940.70540.708840.712260.715660.719040.7224
0.60.725750.729070.732370.735650.738910.742150.745370.748570.751750.7549
0.70.758040.761150.764240.76730.770350.773370.776370.779350.78230.78524
0.80.788140.791030.793890.796730.799550.802340.805110.807850.810570.81327
0.90.815940.818590.821210.823810.826390.828940.831470.833980.836460.83891
10.841340.843750.846140.848490.850830.853140.855430.857690.859930.86214
1.10.864330.86650.868640.870760.872860.874930.876980.8790.8810.88298
1.20.884930.886860.888770.890650.892510.894350.896170.897960.899730.90147
1.30.90320.90490.906580.908240.909880.911490.913090.914660.916210.91774
1.40.919240.920730.92220.923640.925070.926470.927850.929220.930560.93189
1.50.933190.934480.935740.936990.938220.939430.940620.941790.942950.94408
1.60.94520.94630.947380.948450.94950.950530.951540.952540.953520.95449
1.70.955430.956370.957280.958180.959070.959940.96080.961640.962460.96327
1.80.964070.964850.965620.966380.967120.967840.968560.969260.969950.97062
1.90.971280.971930.972570.97320.973810.974410.9750.975580.976150.9767
20.977250.977780.978310.978820.979320.979820.98030.980770.981240.98169
2.10.982140.982570.9830.983410.983820.984220.984610.9850.985370.98574
2.20.98610.986450.986790.987130.987450.987780.988090.98840.98870.98899
2.30.989280.989560.989830.99010.990360.990610.990860.991110.991340.99158
2.40.99180.992020.992240.992450.992660.992860.993050.993240.993430.99361
2.50.993790.993960.994130.99430.994460.994610.994770.994920.995060.9952
2.60.995340.995470.99560.995730.995850.995980.996090.996210.996320.99643
2.70.996530.996640.996740.996830.996930.997020.997110.99720.997280.99736
2.80.997440.997520.99760.997670.997740.997810.997880.997950.998010.99807
2.90.998130.998190.998250.998310.998360.998410.998460.998510.998560.99861
30.998650.998690.998740.998780.998820.998860.998890.998930.998960.999
3.10.999030.999060.99910.999130.999160.999180.999210.999240.999260.99929
3.20.999310.999340.999360.999380.99940.999420.999440.999460.999480.9995
3.30.999520.999530.999550.999570.999580.99960.999610.999620.999640.99965
3.40.999660.999680.999690.99970.999710.999720.999730.999740.999750.99976
3.50.999770.999780.999780.999790.99980.999810.999810.999820.999830.99983
3.60.999840.999850.999850.999860.999860.999870.999870.999880.999880.99989
3.70.999890.99990.99990.99990.999910.999910.999920.999920.999920.99992
3.80.999930.999930.999930.999940.999940.999940.999940.999950.999950.99995
3.90.999950.999950.999960.999960.999960.999960.999960.999960.999970.99997
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How to Calculate Z Score?

Let's take an example to understand how z-score is applied in our real-life situations and how we can calculate it using z-table.

Suppose there are 100 students who gave the mathematics exam. Soham is among them and he gets 80 marks(x) out of 100. The average score of the full class is 63(µ) and the standard deviation is 30(σ). Now find out how well Soham performed compared to other students.

To determine this situation, firstly, we need to calculate the z-score with respect to his actual exam marks. After that, we will use the z table to find how well he performed as compared to other peers.

We can find the Z score using the below formula:

Z Score =  
(x - μ)
σ

Where,
x = Observed Value
μ = Mean
σ = Standard Deviation

So, place the values in formula:

Z Score =  
(80 - 63)
30
  = 0.57

Also, you can use our Z-Score Calculator to get rid of the manual calculation.

How to use Z Table?

To check how well Soham performed, we need to find the percentage of highest and lowest scores of other students. For this, we will use a Z-Table(Standard Normal Distribution Table). So, keep it handy.

As we all know that there are two z-tables with positive and negative values. If we get a z-score positive then we will use a positive table. Similarly, if we get a negative z-score, then we will use the negative table.

In Soham's case, we will use the positive table because we get a positive z-score of 0.57.

Now we have to find out the corresponding probability from the table. It's very easy. Just follow the instructions below.

1) Check the first two digits on Y-axis

In our case, it is "0.5".

Check first two digits on Y-axis
2) Check second decimal number on X-axis

The second step is to look at the second decimal number on X-axis. In this case, it is "0.07".

Check second decimal number on X-axis
3) Join the X and Y axis
Join the X and Y axis

As a result, we get 0.71566

4) Convert resultant value into percentage

Multiply resultant value by 100 to get a percentage score. Or you can use the Online Percentage Calculator.

So, 0.71566 × 100 = 71.57%

It means almost 72% of students got lower marks than Soham and 28% got higher.

72% out of 100 = 72.

So, we can say that Soham performed well than other 72 students.

Negative Z Table

Negative Z Table

Positive Z Score Table

Positive Z Score Table

Conclusion

Above all discussion was about how to calculate Z Score and how to use Z Table. Now, it's your turn to use it and determine probabilities of any situation.