I found an abandoned kitten, and I don't know how old he is? He is around 25-30cm long and 15 cm high.

Are his eyes and ears open? If so, then he's at least a week old.

If he's up and moving around and running and playing, then he's at least 3-4 weeks.

If he's started to get his adult coat (losing the fluffy look in favor of shinier fur), then he's at 3-4 months old.

Anything more exact than that is nearly impossible without being able to actually examine him. You might be able to take him to an area vet to be weighed and aged, either cheaply or for free.

20.35 CET Just saw answer helpful since today I had a unexpected visitor coming to our hacienda so tiny so afraid shaking and can hardly see It means eyes were recently open after birth How it can survive without its mother (hmmm cat) Now my Kitty the kindest cutest girl cat pulled in and gave her "milk" (girl cats have at least 6 or 8 milkies for kittens) and she also "produce" milk since start my Kitty Wow wonderful this kitten needs immidiate help and it was so brave and finally after a few hours to try to soften her she actually entered into my house then she ran into the front door first or second chock for this kitten first to leave its mama and then bang into door Its so small and so tiny I was so worried I rushed back home after groceries and my Kitty she was hiding with kitten somewhere so they are protecting the kitten and gives the kitten stand in "milk" so what to do now I can't afford kitten milk to buy I hope Kitty gives it some though and then when do they start eat real meat (cats are at least big ctas carnavours predators so to speak they hunt very skillfully) unless they are lazying around for "free" food of course (just like a lazy friend or something) They need help cats really I can't believe that its mother is not around and kitten has eloped from somewhere and end up with me and My Kitty (Kitty was orphan when I met her in August 2011 since then she stays loyal with me not still adjust to me still wild or some trauma ha s happened to her. Oh My god help Jesus what to do next now after about a afternoons days time its inside mi casa (my house) and gets warm it was shaking I was so relieved it had to enter It was so cold for weeks as long as this kitten was born since I guess so no wonder she was shaking like a leaf Oh my god where is my camera she is comletely quiet not a sound I don't even no she is in the house right now oh my god I am now going to try to use psychology and feed the kitten I must be only 2 two or 3 three weeks old and it was just born then and it was cold in start of June quite cold I had to have heaters actually no wonder its cold what a chock Where is the mother I think she now is slowly warming herself (my other cats are outdoor cats also not use to be inside a house since I live in on a farm (ex-farm) Ok now I have to check football middle of Eiro 2012 and completely changed plans today can't open doors and check it doesn't fall down in water or in the toilet and stuff its very tiny Ciao alll cat kitten rescuers oot there do all kitten a favor and help them with a little of your income for some little food they need vcat portions at öeast or only two times a day and of course liqiud like humans I have now to buy formula (as the human one) and cat replacing milk for the cat its essential for the smalllest cats to have that nutrition or immune system will be bad just like all living creatures!! And I don't even have my own babies and no bfriend or no one to help out my neighbours don't care they care of themselves only True