The amount of cover you need will depend on your own personal circumstance, there is no one-size-fits-all answer. The factors you may need to consider include covering;
If you are using the policy to cover a mortgage then the policy term should be the same as the remaining length of your mortgage. If you are using the policy for family protection people often choose a term that provides cover until their children reach independence. The choice is yours.
The amount of cover - your monthly premium will be higher if you need a large cover amount.
The length of cover - like with cover amount, the longer you need cover for the higher your monthly premium could be.
Your age - monthly premiums are usually lower the younger you are.
Single or joint policy - the cost of two people jointly covered will be cheaper than two separate individual polices.
If you smoke - being a non smoker will typically mean your premiums are lower than if you smoke.