(
a
11
…
a
1
(
q
+
1
)
0
…
…
…
0
⋮
⋱
⋱
⋱
⋮
a
(
p
+
1
)
1
⋱
⋱
⋱
⋮
0
⋱
⋱
⋱
⋱
⋮
⋮
⋱
⋱
⋱
⋱
0
⋮
⋱
⋱
⋱
a
(
n
−
q
)
n
⋮
⋱
⋱
⋱
⋮
0
…
…
…
0
a
n
(
n
−
p
)
…
a
n
n
)
{\displaystyle \left({\begin{matrix}a_{11}&\ldots &a_{1(q+1)}&0&\ldots &\ldots &\ldots &0\\\vdots &\ddots &&\ddots &\ddots &&&\vdots \\a_{(p+1)1}&&\ddots &&\ddots &\ddots &&\vdots \\0&\ddots &&\ddots &&\ddots &\ddots &\vdots \\\vdots &\ddots &\ddots &&\ddots &&\ddots &0\\\vdots &&\ddots &\ddots &&\ddots &&a_{(n-q)n}\\\vdots &&&\ddots &\ddots &&\ddots &\vdots \\0&\ldots &\ldots &\ldots &0&a_{n(n-p)}&\ldots &a_{nn}\end{matrix}}\right)}
Širina pasu pove najmanjše število pasov, v katerem so stisnjeni neničelni elementi.
Če je matrika
A
{\displaystyle A\!\,}
n
×
n
{\displaystyle n\times n\!\,}
a
i
j
{\displaystyle a_{ij}\!\,}
k
1
{\displaystyle k_{1}\!\,}
k
2
{\displaystyle k_{2}\!\,}
a
i
,
j
=
0
kadar je
j
<
i
−
k
1
ali
j
>
i
+
k
2
;
k
1
,
k
2
≥
0
,
{\displaystyle a_{i,j}=0\quad {\mbox{ kadar je }}\quad j<i-k_{1}\quad {\mbox{ ali}}\quad j>i+k_{2};\quad k_{1},k_{2}\geq 0\!\,,}
potem se števili
k
1
{\displaystyle k_{1}\!\,}
k
2
{\displaystyle k_{2}\!\,}
leva in desna polovica pasovne širine .
Pasovna širina (celotna pasovna širina) pa je enaka
k
1
+
k
2
+
1
{\displaystyle k_{1}+k_{2}+1\!\,}
Kadar je
k
1
=
k
2
=
0
{\displaystyle k_{1}=k_{2}=0\!\,}
diagonalna . Matrika s
k
1
=
k
2
=
1
{\displaystyle k_{1}=k_{2}=1\!\,}
tridiagonalna , kadar pa je
k
1
=
k
2
=
2
{\displaystyle k_{1}=k_{2}=2\!\,}
pentadiagonalna matrika . Če je
k
1
=
0
{\displaystyle k_{1}=0\!\,}
k
2
=
n
−
1
{\displaystyle k_{2}=n-1\!\,}
trikotna matrika , za
k
1
=
n
−
1
{\displaystyle k_{1}=n-1\!\,}
k
2
=
0
{\displaystyle k_{2}=0\!\,}
