Ratios decide how many children you can take, and so how much you can earn, which makes them worth understanding properly instead of half remembering a number from your pre-registration course. The rules for childminders in England are in the EYFS, and the basic version fits in one sentence.
The basic childminder ratio
A childminder can care for up to six children under the age of 8 at any one time. No more than three of them can be young children, meaning children up to 31 August after their fifth birthday, and normally only one can be under the age of one.
Your own children count, and so do any children you foster, if they're under 8 and in the setting. That catches a lot of people out: with a two-year-old of your own, you have two young children's places left, not three.
Children aged 8 and over don't count towards these numbers, but you still have to make sure caring for them doesn't affect the quality or safety of care for the younger ones.
The exceptions
The EYFS allows some flexibility for babies, siblings and continuity of care. You can care for more than one child under one if they're siblings, if one is your own baby, or to keep continuity for a child you already look after. Any exception has to meet the children's needs, and Ofsted or your agency will want to know you've thought about how you'd manage safely, including in an emergency.
There's also an exception for children aged 4 and 5 who are at school. You can care for them before and after school and in the holidays alongside three other young children, as long as the total stays within six children under 8.
Mistakes tend to happen with the exceptions, so read section 3 of the current EYFS for childminders yourself before relying on one, especially if your setup is unusual.
Assistants and co-childminders
If you work with an assistant or another childminder, each of you can care for the number of children allowed for one childminder. Two childminders together, or a childminder and an assistant, can care for up to twelve children under 8 between them, with the limits on young children and babies applying to each adult.
An assistant can be left in sole charge of children for up to two hours in a single day, and only with parents' permission. Nobody under 17 counts in ratios, apart from apprentices aged 16 or over.
Space can limit you first
Your indoor space has its own minimums per child: 3.5 square metres for children under two, 2.5 for two-year-olds and 2.3 for children aged three to five. In a smaller home it's often space that sets your real limit. There's more on measuring in my floor space guide.
Ratios and your contract
Ratios affect what you can promise in your contract. If a family asks to change days or add hours, you can only agree if the place fits within your ratios on those days, so say that in writing from the start. GoChildmind includes a line saying changes depend on space within your ratios, along with your statement that you always stay within them.