Data released on Friday by the Government Office for Science and the Scientific Advisory Group for Emergencies (Sage) shows the estimate for R across the UK is between 0.9 and 1.1.
The growth rate of coronavirus transmission, which reflects how quickly the number of infections is changing day by day, has increased slightly.
For the whole of the UK, the latest growth rate is between minus 1% and plus 2% per day, a slight change from between minus 2% and plus 1% last week.
The growth rate means the number of new infections is somewhere between shrinking by 1% and growing by 2% every day.
The most likely value is towards the middle of the range, experts advising the Government say.
The R number represents the number of people each Covid-19 positive person goes on to infect.
In England, the R is between 0.9 and one, and the growth rate is minus 2% to plus 1%.
But the experts say the numbers should be interpreted with caution.
This is because when case levels are low, there is a high degree of variability in transmission and a single average value may not accurately reflect the way infections are changing throughout the region.
Local outbreaks, for example, can skew the numbers, even though overall transmission may be low across the region.
Scientists say that, when disease incidence is low, or there is a high degree of variability in regional transmission, the estimates of R and the growth rate “should not be treated as robust enough to inform policy decisions alone”.
It is more appropriate to identify local hotspots through, for example, monitoring numbers of cases, hospital admissions, and deaths, the team behind the data said.
Recent changes in transmission are not yet fully reflected in the estimates because the data used to calculate R and growth rate reflect the situation from a few weeks ago.
Therefore, the figures published on Friday more accurately represent the average situation over the past few weeks rather than the current situation.
In the East of England, the growth rate is between minus 5% and zero, and the R number is 0.8-1.
In London, the growth rate is between minus 3% and plus 2%, and the capital’s R rate is at 0.9-1.1.
The Midlands has a growth rate of between minus 6% and zero the region’s R number is 0.8-1.
In the North East and Yorkshire, the growth rate is between minus 3% and zero, while its R value is 0.8-1.
The growth rate in the North West is between minus 3% and zero. The R value is 0.8-1.
In the South East, the growth rate is between minus 4% and plus 1%. The R value in the region is 0.8-1.
The South West has a growth rate of between minus 4% and plus 1%. Its R value is 0.8-1.1.