Student's T Critical Values

Conf. Level

50%

80%

90%

95%

98%

99%

One Tail

0.250

0.100

0.050

0.025

0.010

0.005

Two Tail

0.500

0.200

0.100

0.050

0.020

0.010

df = 1

1.000

3.078

6.314

12.706

31.821

63.657

2

0.816

1.886

2.920

4.303

6.965

9.925

3

0.765

1.638

2.353

3.182

4.541

5.841

4

0.741

1.533

2.132

2.776

3.747

4.604

5

0.727

1.476

2.015

2.571

3.365

4.032

6

0.718

1.440

1.943

2.447

3.143

3.707

7

0.711

1.415

1.895

2.365

2.998

3.499

8

0.706

1.397

1.860

2.306

2.896

3.355

9

0.703

1.383

1.833

2.262

2.821

3.250

10

0.700

1.372

1.812

2.228

2.764

3.169

11

0.697

1.363

1.796

2.201

2.718

3.106

12

0.695

1.356

1.782

2.179

2.681

3.055

13

0.694

1.350

1.771

2.160

2.650

3.012

14

0.692

1.345

1.761

2.145

2.624

2.977

15

0.691

1.341

1.753

2.131

2.602

2.947

16

0.690

1.337

1.746

2.120

2.583

2.921

17

0.689

1.333

1.740

2.110

2.567

2.898

18

0.688

1.330

1.734

2.101

2.552

2.878

19

0.688

1.328

1.729

2.093

2.539

2.861

20

0.687

1.325

1.725

2.086

2.528

2.845

21

0.686

1.323

1.721

2.080

2.518

2.831

22

0.686

1.321

1.717

2.074

2.508

2.819

23

0.685

1.319

1.714

2.069

2.500

2.807

24

0.685

1.318

1.711

2.064

2.492

2.797

25

0.684

1.316

1.708

2.060

2.485

2.787

26

0.684

1.315

1.706

2.056

2.479

2.779

27

0.684

1.314

1.703

2.052

2.473

2.771

28

0.683

1.313

1.701

2.048

2.467

2.763

29

0.683

1.311

1.699

2.045

2.462

2.756

30

0.683

1.310

1.697

2.042

2.457

2.750

40

0.681

1.303

1.684

2.021

2.423

2.704

50

0.679

1.299

1.676

2.009

2.403

2.678

60

0.679

1.296

1.671

2.000

2.390

2.660

70

0.678

1.294

1.667

1.994

2.381

2.648

80

0.678

1.292

1.664

1.990

2.374

2.639

90

0.677

1.291

1.662

1.987

2.368

2.632

100

0.677

1.290

1.660

1.984

2.364

2.626

z

0.674

1.282

1.645

1.960

2.326

2.576