Interactive Z Table

Look up a z score, see the exact row and column, or reverse a probability into z without leaving the table.

Enter a finite z score from −8 to 8.

Left-tail probability0.97500297.5002%
Left-tail area for z equals 1.96

Φ(1.96) = P(Z ≤ 1.96) = 0.975002

Table lookup1.9 row + .06 column → z = 1.96 → Φ(z) = 0.9750Exact calculation shown above; the printed table rounds to four decimals.
FULL STANDARD NORMAL TABLE

Left cumulative area Φ(z) = P(Z ≤ z)

Find the signed row for ones and tenths, then the column for hundredths. Every cell is a left-tail probability rounded to four decimals.

Positive z-score table
z.00.01.02.03.04.05.06.07.08.09
0.00.50000.50400.50800.51200.51600.51990.52390.52790.53190.5359
0.10.53980.54380.54780.55170.55570.55960.56360.56750.57140.5753
0.20.57930.58320.58710.59100.59480.59870.60260.60640.61030.6141
0.30.61790.62170.62550.62930.63310.63680.64060.64430.64800.6517
0.40.65540.65910.66280.66640.67000.67360.67720.68080.68440.6879
0.50.69150.69500.69850.70190.70540.70880.71230.71570.71900.7224
0.60.72570.72910.73240.73570.73890.74220.74540.74860.75170.7549
0.70.75800.76110.76420.76730.77040.77340.77640.77940.78230.7852
0.80.78810.79100.79390.79670.79950.80230.80510.80780.81060.8133
0.90.81590.81860.82120.82380.82640.82890.83150.83400.83650.8389
1.00.84130.84380.84610.84850.85080.85310.85540.85770.85990.8621
1.10.86430.86650.86860.87080.87290.87490.87700.87900.88100.8830
1.20.88490.88690.88880.89070.89250.89440.89620.89800.89970.9015
1.30.90320.90490.90660.90820.90990.91150.91310.91470.91620.9177
1.40.91920.92070.92220.92360.92510.92650.92790.92920.93060.9319
1.50.93320.93450.93570.93700.93820.93940.94060.94180.94290.9441
1.60.94520.94630.94740.94840.94950.95050.95150.95250.95350.9545
1.70.95540.95640.95730.95820.95910.95990.96080.96160.96250.9633
1.80.96410.96490.96560.96640.96710.96780.96860.96930.96990.9706
1.90.97130.97190.97260.97320.97380.97440.97500.97560.97610.9767
2.00.97720.97780.97830.97880.97930.97980.98030.98080.98120.9817
2.10.98210.98260.98300.98340.98380.98420.98460.98500.98540.9857
2.20.98610.98640.98680.98710.98750.98780.98810.98840.98870.9890
2.30.98930.98960.98980.99010.99040.99060.99090.99110.99130.9916
2.40.99180.99200.99220.99250.99270.99290.99310.99320.99340.9936
2.50.99380.99400.99410.99430.99450.99460.99480.99490.99510.9952
2.60.99530.99550.99560.99570.99590.99600.99610.99620.99630.9964
2.70.99650.99660.99670.99680.99690.99700.99710.99720.99730.9974
2.80.99740.99750.99760.99770.99770.99780.99790.99790.99800.9981
2.90.99810.99820.99820.99830.99840.99840.99850.99850.99860.9986
3.00.99870.99870.99870.99880.99880.99890.99890.99890.99900.9990
3.10.99900.99910.99910.99910.99920.99920.99920.99920.99930.9993
3.20.99930.99930.99940.99940.99940.99940.99940.99950.99950.9995
3.30.99950.99950.99950.99960.99960.99960.99960.99960.99960.9997
3.40.99970.99970.99970.99970.99970.99970.99970.99970.99970.9998
3.50.99980.99980.99980.99980.99980.99980.99980.99980.99980.9998
3.60.99980.99980.99990.99990.99990.99990.99990.99990.99990.9999
3.70.99990.99990.99990.99990.99990.99990.99990.99990.99990.9999
3.80.99990.99990.99990.99990.99990.99990.99990.99990.99990.9999
3.91.00001.00001.00001.00001.00001.00001.00001.00001.00001.0000

This table is cumulative area to the left

Every printed cell is Φ(z) = P(Z ≤ z). A left-tail lookup can use the cell directly. A right-tail lookup uses the opposite area, and a two-tailed lookup doubles the area beyond |z|. The tool labels the convention so a value is not silently read from the wrong kind of table.

Follow the highlighted row, column, and cell

Split a two-decimal z score into its signed ones-and-tenths row and its hundredths column. For z = 1.96, use row 1.9 and column .06. The tool highlights all three parts and repeats the path beside the result. More precise z scores are calculated directly and mapped to the nearest printed cell without pretending the table has extra precision.

Reverse a probability without guessing the nearest cell

Probability-to-z mode calculates the inverse standard normal value, then shows the two table cells surrounding it. For left probability 0.9500, the neighboring entries are 1.64 / 0.9495 and 1.65 / 0.9505; interpolation gives about 1.645. The unrounded numerical inverse result remains separate from the rounded table explanation.

0.95 percentile is not the same as central 95%

A left cumulative probability of 0.95 corresponds to z ≈ 1.645. A central 95% interval leaves 2.5% in each tail, so its critical values are about ±1.96. Select the tail definition before interpreting the number.

Scope and accuracy

The calculator uses browser-side numerical approximations and prints table cells to four decimals. It is a standard-normal reference, not a test selector, clinical growth-chart z score, bone-density T/Z score, diagnosis, or statistical consulting service.

Frequently asked questions

What is a z-score table used for?

A standard normal z table gives the cumulative probability for a z score. This table uses Φ(z) = P(Z ≤ z), the area to the left. Enter a z score to highlight its row, hundredths column, and intersection cell.

What is 0.95 in the z table?

A left cumulative probability of 0.9500 lies between z = 1.64 and 1.65, so interpolation gives about 1.645. Do not confuse that percentile with a central 95% interval, whose two-sided critical values are about ±1.96.

How do I look up z = 1.96?

Use the 1.9 row and the .06 column. Their intersection is 0.9750, meaning 97.50% of the standard normal distribution lies at or below z = 1.96.

What is the z-score formula?

For a raw value x with mean μ and standard deviation σ, z = (x − μ) / σ. This page expects the resulting z score; it does not calculate or validate the mean and standard deviation.

How do negative z scores work?

Negative z scores are below the mean. By symmetry, Φ(−z) = 1 − Φ(z). The negative table keeps the signed row and hundredths column visible so −1.96 maps to 0.0250.

How do I find a two-tailed probability?

For a z score, the total two-tailed probability is 2 × Φ(−|z|). In reverse mode, a two-tailed probability of 0.05 gives critical values near ±1.96.

What is the difference between a z table and a t table?

A z table uses the standard normal distribution. A t table uses Student's t distribution and depends on degrees of freedom. This page does not choose a statistical test or replace a t table.

Sources and method

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