points to scores reference

1     -5
2-3   -4
4-5   -3
6-7   -2
8-9   -1
10-11  0
12-13  1
14-15  2
16-17  3
18-19  4
20-21  5
22-23  6
24-25  7
26-27  8
28-29  9
30-31 10

point buy

The RAW only allow players to buy stats up to 15 or as low as 8. That's kinda lame so here's a better table:

3     -9
4     -6
5     -4
6     -2
7     -1
8      0
9      1
10     2
11     3
12     4
13     5
14     7
15     9
16    12
17    15
18    19

racial increases

Strength
    Moutain dwarf +2
    Dragonborn +2
    Half-orc +2
    Human +1
Dexterity
    Elf +2
    Hafling +2
    Forest Gnome +1
    Human +1
Constitution
    Dwarf +2
    Stout hafling +1
    Rock gnome +1
    Half-orc +1
    Human +1
Intelligence
    Gnome +2
    High elf +1
    Teifling +1
    Human +1
Wisdom
    Hill dwarf +1
    Wood elf +1
    Human +1
Charisma
    Half-elf +2
    Tiefling +1
    Drow +1
    Dragonborn +1
    Lightfoot halfling +1
    Human +1