Critical Values in the t-Distribution

 

Level of Significance (α) for Directional (One-Tailed) Tests

 

.10

.05

.025

.01

.005

.0005

 

 

 

 

 

 

 

 

Level of Significance (α) for Non-Directional (Two-Tailed) Tests

df

.20

.10

.05

.02

.01

.001

1

3.078

6.314

12.706

31.821

63.656

636.578

2

1.886

2.920

4.303

6.965

9.925

31.600

3

1.638

2.353

3.182

4.541

5.841

12.924

4

1.533

2.132

2.776

3.747

4.604

8.610

5

1.476

2.015

2.571

3.365

4.032

6.869

6

1.440

1.943

2.447

3.143

3.707

5.959

7

1.415

1.895

2.365

2.998

3.499

5.408

8

1.397

1.860

2.306

2.896

3.355

5.041

9

1.383

1.833

2.262

2.821

3.250

4.781

10

1.372

1.812

2.228

2.764

3.169

4.587

11

1.363

1.796

2.201

2.718

3.106

4.437

12

1.356

1.782

2.179

2.681

3.055

4.318

13

1.350

1.771

2.160

2.650

3.012

4.221

14

1.345

1.761

2.145

2.624

2.977

4.140

15

1.341

1.753

2.131

2.602

2.947

4.073

16

1.337

1.746

2.120

2.583

2.921

4.015

17

1.333

1.740

2.110

2.567

2.898

3.965

18

1.330

1.734

2.101

2.552

2.878

3.922

19

1.328

1.729

2.093

2.539

2.861

3.883

20

1.325

1.725

2.086

2.528

2.845

3.850

21

1.323

1.721

2.080

2.518

2.831

3.819

22

1.321

1.717

2.074

2.508

2.819

3.792

23

1.319

1.714

2.069

2.500

2.807

3.768

24

1.318

1.711

2.064

2.492

2.797

3.745

25

1.316

1.708

2.060

2.485

2.787

3.725

26

1.315

1.706

2.056

2.479

2.779

3.707

27

1.314

1.703

2.052

2.473

2.771

3.689

28

1.313

1.701

2.048

2.467

2.763

3.674

29

1.311

1.699

2.045

2.462

2.756

3.660

30

1.310

1.697

2.042

2.457

2.750

3.646

40

1.303

1.684

2.021

2.423

2.704

3.551

60

1.296

1.671

2.000

2.390

2.660

3.460

120

1.289

1.658

1.980

2.358

2.617

3.373

1.282

1.645

1.960

2.326

2.576

3.291