Does anyone know what is the amount if savings required for the FLR visa if your spouse is a carer?
There is no minimum amount.
The requirement for if your sponsor receives carer's allowance is that you have 'adequate maintenance' to support yourselves without accessing public funds. 'Adequate maintenance' is calculated as having at least as much left over each week after rent and council tax as a UK couple (plus any kids) would receive in income support from the government.
A UK couple receives £114.85 per week, and each child receives £66.90 in income support.
So, if there are no dependant children in your household (UK or non-UK citizens) you have to show:
Weekly Income - (weekly rent + weekly council tax) = £114.85 or more
If you have self-employment income, you would need to show all the evidence required for self-employment as per Appendix FM 1.7.
If you have no income and are using savings, then you would divide up your savings into weekly amounts and use that as your 'weekly income'. All of the savings can be considered (whereas normally only the amount above £16,000 can be used).
Say your rent is £500 per month, so about £125 per week, and your council tax is £100 per month, so £25 per week, that would be a weekly total of £150.
So, you would need at least £150 + £114.85 = £264.85 in weekly income or savings to meet the requirement.
The requirements don't specify how long the savings have to last, but assuming you were covering the entire 2.5 years (£264.85 x 130 weeks), that would be about £34,500.