According to Universal France, STEP BY STEP by NEW KIDS ON THE BLOCK has sold 20,000,000 copies worldwide. The album sold best in United States (3,000,000 copies), Canada (700,000 copies) and Germany (500,000 copies).
STEP BY STEP certifications and sales
| Country / region | Sales | Certification / source | Certification date / sales as of | |
 Australia |
35,000 | 1x Gold | JUNE 1990 |
Australia Sales: 35,000
Certification / note: 1x Gold
Certification Date / sales as of: JUNE 1990
|
 Austria |
50,000 | 1x Platinum | 7 August, 1991 |
Austria Sales: 50,000
Certification / note: 1x Platinum
Certification Date / sales as of: 7 August, 1991
|
 Brazil |
100,000 | 1x Gold | 1990 |
Brazil Sales: 100,000
Certification / note: 1x Gold
Certification Date / sales as of: 1990
|
 Canada |
700,000 | 7x Platinum | 1991 |
Canada Sales: 700,000
Certification / note: 7x Platinum
Certification Date / sales as of: 1991
|
 Finland |
50,100 | IFPI Finland |
Finland Sales: 50,100
Certification / note: IFPI Finland
Certification Date / sales as of:
|
|
 France |
300,000 | 1x Platinum | 1991 |
France Sales: 300,000
Certification / note: 1x Platinum
Certification Date / sales as of: 1991
|
 Germany |
500,000 | 1x Platinum | 1991 |
Germany Sales: 500,000
Certification / note: 1x Platinum
Certification Date / sales as of: 1991
|
 Japan |
210,480 | 1x Platinum | March 1992 |
Japan Sales: 210,480
Certification / note: 1x Platinum
Certification Date / sales as of: March 1992
|
 Netherlands |
50,000 | 1x Gold | 1990 |
Netherlands Sales: 50,000
Certification / note: 1x Gold
Certification Date / sales as of: 1990
|
 New Zealand |
15,000 | 1x Platinum |
New Zealand Sales: 15,000
Certification / note: 1x Platinum
Certification Date / sales as of:
|
|
 Norway |
31,858 | Year-end list | 1990 |
Norway Sales: 31,858
Certification / note: Year-end list
Certification Date / sales as of: 1990
|
 Spain |
100,000 | 1x Platinum | 1990 |
Spain Sales: 100,000
Certification / note: 1x Platinum
Certification Date / sales as of: 1990
|
 Sweden |
50,000 | 1x Gold | 14 March, 1991 |
Sweden Sales: 50,000
Certification / note: 1x Gold
Certification Date / sales as of: 14 March, 1991
|
 Switzerland |
50,000 | 1x Platinum | 1991 |
Switzerland Sales: 50,000
Certification / note: 1x Platinum
Certification Date / sales as of: 1991
|
 United Kingdom |
300,000 | 1x Platinum | 1 August, 1990 |
United Kingdom Sales: 300,000
Certification / note: 1x Platinum
Certification Date / sales as of: 1 August, 1990
|
 United States |
3,000,000 | 3x Platinum | 1 August, 1990 |
United States Sales: 3,000,000
Certification / note: 3x Platinum
Certification Date / sales as of: 1 August, 1990
|
| Worldwide sales | 20,000,000 | Universal France |
Total
Sales: 20,000,000
Source: Universal France
|
Year-end chart performance for STEP BY STEP
| Chart 1990 | Rank | Sales |
| Austrian Albums (Ö3 Austria) |
20 | |
| Canadian Albums (RPM) |
12 | |
| Dutch Albums (Album Top 100) |
48 | |
 European Albums (Music & Media) |
9 | |
| German Albums (Offizielle Top 100) |
23 | |
| New Zealand Albums (RMNZ) |
17 | |
| Norwegian Albums (Dagbladet) |
23 | 31,858 |
| Swiss Albums (Schweizer Hitparade) |
26 | |
| UK Albums |
22 | |
| UK Artist Albums |
20 | |
| US Albums (Billboard 200) |
34 | |
| Chart 1991 | Rank | Sales |
| European Albums (Music & Media) |
85 |